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A phylogeny reconstruction of the Dendrophylliidae (Cnidaria, Scleractinia) based on molecular and micromorphological criteria, and its ecological implications
Abstract
Recent molecular phylogenetic studies have shown that most traditional families of zooxanthellate shallow-water scleractinians are polyphyletic, whereas most families mainly composed of deep-sea and azooxanthellate species are monophyletic. In this context, the family Dendrophylliidae (Cnidaria, Scleractinia) has unique features. It shows a remarkable variation of morphological and ecological traits by including species that are either colonial or solitary, zooxanthellate or azooxanthellate, and inhabiting shallow or deep water. Despite this morphological heterogeneity, recent molecular works have confirmed that this family is monophyletic. Nevertheless, what so far is known about the evolutionary relationships within this family, is predominantly based on skeleton macromorphology, while most of its species have remained unstudied from a molecular point of view. Therefore, we analysed 11 dendrophylliid genera, four of which were investigated for the first time, and 30 species at molecular, micromorphological and microstructural levels. We present a robust molecular phylogeny reconstruction based on two mitochondrial markers (COI and the intergenic spacer between COI and 16S) and one nuclear (rDNA), which is used as basis to compare micromorphogical and microstructural character states within the family. The monophyly of the Dendrophylliidae is well supported by molecular data and also by the presence of rapid accretion deposits, which are ca. 5 μm in diameter and arranged in irregular clusters, and fibres that thicken the skeleton organized in small patches of a few micrometres in diameter. However, all genera represented by at least two species are not monophyletic, Tubastraea excluded. They were defined by traditional macromorphological characters that appear affected by convergence, homoplasy and intraspecific variation. Micromorphogical and microstructural analyses do not support the distinction of clades, with the exception of the organization of thickening deposits for the Tubastraea clade.
... Remarks: Despite the branchy development and the extracalicinal budding, as also observed in T. dendroida, T. diaphana and T. micranthus (Cairns & Zibrowius 1997, Cairns 2001, Arrigoni et al. 2014, Yiu & Qiu 2022, T. ramosa sp. nov. is easily distinguished from the three former species due to its irregular monopodial growth pattern. ...
... Tubastraea aurea differs morphologically from T. coccinea due to the size and development of the corallites. It is also important to emphasize that Tubastraea aurea has been considered a valid species in phylogenetic studies developed by Arrigoni et al. (2014), Yiu & Qiu (2022), and Mehrotra et al. (2023). Moreover, Yiu & Qiu (2022) positioned T. aurea as the sister group of T. diaphana. ...
... The importance of the analysis of micromorphology using SEM images has been pointed out by several authors in taxonomic and systematic studies (Budd & Stolarski 2009, 2011, Budd et al. 2012, Benzoni et al. 2012, Arrigoni et al. 2014, Capel et al. 2019, Bastos et al. 2022. Macro and micromorphology data are a powerful diagnostic tool for Scleractinia taxonomy, and useful in studies of species complexes, in which a high degree of morphological variation, and the overlapping of diagnostic characteristics among morphotypes, are expected to hinder the identifications. ...
In Brazil, two species of exotic 'sun corals' have been cited, majorly in ecological studies, over the last two decades. In Bahia State, colonies were registered for the first time in 2008 in a shipwreck in the Todos-os-Santos Bay. Since then, these species have spread locally across artificial and natural environments comprising variable patterns of interspecific morphologies. However, the identifications of these dendrophylliids have been circumstantially influenced by a single morphological aspect, the development of corallites: plocoid colonies have been referred to as Tubastraea coccinea, and dendroid morphotypes as Tubastraea tagusensis. Thus, the main goal of this study was to analyze the patterns of the morphological variation of sun corals from the Bahia State (12 o S, Southwestern Atlantic), inferring their interspecific limits. Skeleton macro and micromorphology analyses provided evidence for the presence of seven species in this coastal section. As a result, we describe four new Tubastraea species: Tubastraea ramosa sp. nov., Tubastraea columnata sp. nov., Tubastraea.grandidentata sp. nov., and Tubastraea megalostoma sp. nov. A new distribution record is reported for Tubastraea faulkneri in Brazil. A morphological diagnosis was developed for all seven Brazilian sun coral species. Finally, two identification keys, the worldwide and the Brazilian Tubastraea species are provided.
... In this work, he not only provided a comprehensive summary of the complex taxonomic history of all extant and extinct genera known at the time, but also diagnosed each based on ten characters (nine morphological, one ecological). The integration of molecular data in subsequent studies however caused a paradigm shift, with multiple later studies (Capel et al., 2020;Yiu et al., 2021;Yiu & Qiu, 2022) supporting the findings of Arrigoni et al. (2014). In particular, a large number of genera were found to be polyphyletic, with little clear indication on which characters (or combination thereof) proposed by Cairns (2001) retained broad diagnostic power among modern dendrophylliid corals. ...
... Attempts to find sequences pertaining to the relevant regions from a single specimen of the closely related family Poritidae were not successful, so thus sequences from multiple specimens of Goniopora columna Dana, 1846 were concatenated for the purposes of our analysis. Sequence information for the Goniopora outgroup used by Arrigoni et al. (2014) could not be found for purposes of review or replication. ...
... Bleached specimens were examined carefully utilising a simple over-the-counter magnifying lens, in conjunction with an Olympus tg6 digital camera. Morphological features were investigated and compared to relevant literature on the Dendrophylliidae (in particular Zibrowius, 1985;Hoeksema & Best, 1991;Cairns, 2001;Cairns & Kitahara, 2012;Arrigoni et al., 2014;Filander et al., 2021;. Additionally, two specimens each of the four soft-substrate species and one specimen each of Cladopsammia gracilis and Tubastraea diaphana were scanned using micro computed tomography (microct). ...
Dendrophylliidae represents one of the most speciose families of scleractinian coral, expressing a wide range of morphological and ecological traits. Recent phylogenetic analyses of the family have indicated that several conventional genera are in need of revision. In the Gulf of Thailand, dendrophylliids are predominantly found on hard-substrate reefs and pinnacles, or on soft-substrate habitats. Soft-substrate habitats in the Gulf of Thailand have been shown to host unique species assemblages and faunal ecology. Here we provided an updated phylogenetic hypothesis for the Dendrophylliidae based on newly sequenced species, and analyses integrating morphology, genetics and ecology. High-resolution Micro- ct was used to create digital versions of the studied species, allowing for non-destructive examination of internal and external features. Our findings allowed for a taxonomic assessment of the genera Heteropsammia and Tubastraea , with the species Balanophyllia ( Eupsammia ) stimpsonii , moved to the genus Tubastraea . They also support the polyphyly of Dendrophyllia and Cladopsammia . In-situ surveys provided population-density information for four dendrophylliid species from soft substrate habitats, indicating that the species Heteropsammia moretonensis may be the most widespread within the Gulf of Thailand. These surveys also provided novel ecological documentation associated with these corals, including protocooperative feeding upon a sea pen by Tubastraea stimpsonii comb. nov., and feeding upon other cnidarians by Heteropsammia spp.
... However, in this paper we consider T. aurea (Quoy & Gaimard, 1833) as the valid name, since the decision to classify it otherwise was based only on the fact that the type locality of this species is in the southern hemisphere, rather than on morphological and phylogenetic analysis. The change in classification contradicted the result of a phylogenetic study showing that it is nested within a clade of Turbastraea (Arrigoni et al. 2014). ...
... Because of this fact, Yiu et al. (2021) removed the lack of this structure from the diagnostic features of this genus. Molecular phylogenetic analysis based on multigene markers (i.e., COI, intergenic spacer between COI and 16S, and a rDNA marker including ITS1, 5.8S, ITS2, and a segment of 18S and 28S) have clarified the classification of Dendrophylliidae (Arrigoni et al. 2014), revealing that, while most other genera of the family represented by at least two species are nonmonophyletic, Tubastraea is monophyletic with a strong bootstrap support. ...
... Polymerase chain reaction (PCR) was conducted using the extracted DNA as templates to amplify the COI, IGR and rDNA. The partial COI (~750 bp) was amplified using primers designed by Arrigoni et al. (2014): COIDENL (5'-CGCTGGGCGTTTTCTACTAA -3') and COIDENR (5'-GAAATCATTCCAAAGCCAGGT -3'). The amplification program consisted of an initial denaturation step of 94°C for 2 min, followed by 35 cycles of 94°C for 30 sec, 53°C for 1 min, 72°C for 1 min and finally a 7 min extension step at 72°C. ...
Tubastraea is a genus of azooxanthellate scleractinian corals belonging to the family Dendrophylliidae, which are commonly called sun corals. This genus currently has only seven recognized species. In this paper, we report three new species of Tubastraea, including T. dendroida sp. nov., which has a tree-like colony, T. violacea sp. nov., which has violet polyps, and T. chloromura sp. nov., which has olive green polyps. These species are distinct in their septal structures, as well as their rDNA sequences including the entire ITS1, 5.8S and ITS2, and a segment of the 18S and 28S genes.
... On the other hand, previous phylogenetic analysis based on mitochondrial DNA (COI gene sequence data) pointed to the monophyly of the family Dendrophylliidae, with Tubastraea aurea and T. coccinea as sister groups (Kitahara et al. 2010). A recent integrative phylogenetic study of Dendrophylliidae based on nuclear and mitochondrial molecular markers as well as microstructural characteristics (e.g., arrangement of skeleton fibers, characteristics of septal teeth and granules) reassured the monophyly of the family and the monophyly of the genus Tubastraea, and found that T. aurea and T. coccinea were distinct species (Arrigoni et al. 2014). ...
... The samples were bathed in xylol to clean the residues and covered with Au/Pd on a Quorum metallizer (model Q150T ES -Nanjing Tansi Technology Co. Ltd.). The photographs were obtained with a SEM-ZEISS EVO-40 Scanning Electron Microscope at the Leopoldo Américo Miguez de Mello Research Center/Petróleo Brasileiro SA(CENPES/PETROBRAS). To verify the identification of the morphotypes, the taxonomic characteristics were compared to the holotypes of the Tubastraea species described earlier (Boschma 1953, Wells 1982, Cairns 1991, Cairns 1994, Cairns 2000, Arrigoni et al. 2014). The entire sample was deposited in the scientific collection of the Instituto de Estudos do Mar Almirante Paulo Moreira, Brazilian Navy (IEAPM). ...
... Microstructural characteristics are important for a more accurate assessment of coral differentiation (Budd et al. 2010) and for the systematics of the Dendrophylliidae (Arrigoni et al. 2014) and were relevant for differentiation in our study (Fig. 7). Additionally, Storlarski (2003) reinforced that the microstructural approach of the coral skeleton was a useful tool to elucidate the evolutionary relationships in the Order Scleractinia. ...
The scleractinian corals of the genus Tubastraea Lesson, 1830 are currently globally dispersed and even so still present a confused taxonomy due to the overlap of morphological characters between the species. In this study, we investigate Tubastraea species previously found in the western Atlantic, based on the molecular marker (ITS gene) and morphology, to determine the accuracy of their descriptions. We identified three morphotypes from Brazil which were genetically delimited into two species: Tubastraea coccinea (Morphotypes I and II) and Tubastraea sp. (Morphotype III). Although morphotype I has morphological patterns of Tubastraea aurea (Quoy & Gaimard, 1833) there was no molecular divergence to support the species differentiation and continue to be recognized as a morphological variant of T. coccinea . The third morphotype is both morphologically and genetically distinct from T. coccinea and is also not representative of the species Tubastraea tagusensis Wells, 1982 despite earlier descriptions describing T. tagusensis in Brazil. Morphotype III exhibited distinct morphological characteristics among the other morphotypes, mainly due to greater polyp projection. In addition, it has fusions between septa, a characteristic that differentiates it from T. tagusensis . Nevertheless, molecular phylogenetic analyses showed that Brazilian Tubastraea fell into two well-supported monophyletic clades, and samples collected in the United States overlapped in both clades. Florida samples exhibited fewer morphotypes and showed greater genetic diversity, presenting haplotypes in four other internal clades. This study highlights the need for an integrative approach to conduct a deeper species delimitation of Tubastraea , essential for managing bioinvasion events by sun corals.
... In situ species identification of unifacial plating Turbinaria corals is challenging. At a species level, existing studies based on cytochrome oxidase I (COI) and rDNA show that most species are polyphyletic (Shimpi et al., 2019) and there is a high level of genetic overlap amongst morphospecies and particularly between Turbinaria mesenterina and T. reniformis (Arrigoni et al., 2014). With this in mind, we included three general morphotypes in our collections-T. ...
... DNA extractions were used at neat or 1:5 dilutions to amplify two mitochondrial DNA fragments. These were COI and the Intergenomic Repeat area (IGR), previously shown to provide informative signal in this taxon (Arrigoni et al., 2014) (see Appendix S1: (Leigh & Bryant, 2015). The museum vouchered specimens were included in this analysis to assist species identification. ...
... *FIS values significantly greater than zero (p ≤ 0.05). Despite common use of COI for phylogeographic and phylogenetic studies (Arrigoni et al., 2014) neither COI nor IGR data could fully discriminate the six Turbinaria species included in this study. The lack of species monophyly likely indicates that these morphospecies are recently diverged, or that ancestral polymorphisms have been retained due to the unusually slow rate of mitogenome evolution in corals (Romano & Palumbi, 1996). ...
Aim
Genetic connectivity is a key component of species resilience to climate change in terms of recovery capacity following disturbance and capacity to disperse to novel locations as the climate warms and isotherms shift poleward. We aimed to strengthen our understanding of resilience in this context by characterizing patterns of connectivity and genetic diversity in a broadcast spawning coral across a tropical–temperate transition zone. We hypothesize genetic differentiation between tropical and temperate populations and decreasing genetic diversity with higher latitudes.
Location
Western Australia (WA).
Taxon
Turbinaria species complex. Turbinaria ‘reniformis’ Oken, 1815 (Scleractinia: Dendrophylliidae).
Methods
A total of 930 target corals were sampled from 10 locations between 13 and 32° latitude spanning a 9°C mean temperature range. In situ species identification of T. reniformis is hindered by morphological plasticity and homoplasy with sister species. We combined Sanger sequencing of two mitochondrial DNA markers and high‐throughput genotyping by sequencing (GBS) to isolate a single genetic Turbinaria lineage from our dataset through which patterns of genetic flow and diversity along the WA coastline could be explored using population‐ and individual‐based clustering analyses.
Results
Mitochondrial DNA sequence variation was low among Turbinaria samples and could not resolve individual species. Using GBS, we identified three genetically distinct lineages. Subsequent analyses within one of these lineages revealed strong spatial subdivision with 2–3 genetic clusters. While temperate populations were genetically diverged from more tropical sites, we did not observe declines in genetic diversity with latitude.
Main conclusions
Tropical populations of T. ‘reniformis’ in Western Australia exhibit strong genetic connectivity, which extends to a southern limit at sub‐tropical Shark Bay. Temperate populations are genetically isolated from their tropical counterparts but have relatively high genetic diversity. While the maintenance of genetic variation in temperate populations may provide some resilience to future climate scenarios, their isolation may increase their vulnerability.
... A study inferring interfamily relationships confirmed it as a well-supported monophyletic scleractinian family composed of shallow to deep-water azooxanthellate and zooxanthellate species (Kitahara et al. 2010). Yet, further examination of the systematics within the Dendrophylliidae (Arrigoni et al. 2014) revealed polyphyletic relationships in some of the dendrophylliid genera, including Balanophyllia Wood, 1844, Cladopsammia Lacaze-Duthiers, 1897, Dendrophyllia de Blainville, 1830, Rhizopsammia Verrill, 1870and Turbinaria Oken,1815. They also noted that the morphological characters used by Cairns (2001) to distinguish dendrophylliid taxa may be insufficient in inferring the evolutionary changes and speciation in this family. ...
... Among the 11 genera examined by Arrigoni et al. (2014), Tubastraea Lesson, 1830 represented a monophyletic clade. The genus is characterized by six characters: 1), colonial coralla firmly attached and encrusting; 2), septa cycles hexamerally arranged and typically inserted with spongy columella; 3), septa not arranged in a Pourtalès plan; 4), corallum with a rough texture; 5), colony developing from a common basal coenosteum by budding, with clear connection among polyps; 6), columella small to moderate in size and lacks an epitheca (Cairns 2001;Cairns & Kitahara 2012). ...
... Photographs of the specimens were taken using an Olympus OM-D EM1markII with a M. Zuiko Digital ED 60mm f2.8 Macro lens. Morphological characters defined by Cairns (2001); Cairns & Kitahara (2012) and Arrigoni et al. (2014) were used for species identification. They included whole colony size, corallite size, fossa depth, intercorallite distance and septa arrangement. ...
Tubastraea, commonly known as sun coral, is a genus of brightly coloured azooxanthellate corals in the family Dendrophylliidae. The diversity of this genus is low, with only seven recognized species. Herein, we describe Tubastraea megacorallita sp. nov. from Hong Kong based on morphological and molecular analyses. This new species exhibits several characteristics of the genus including being colonial, having a rough texture of corallum and no epitheca. It can be distinguished from its congenerics by bigger corallites, and the Pourtalès plan arrangement of its septa. The rDNA gene sequences (consisting of ITS1, 5.8S, ITS2, 18S and 28S) showed 2.45–5.18% divergence from those of its closest relatives, T. coccinea and T. micranthus.
... All subclades were highly supported in both BI and ML analyses, resulting in a stable phylogenetic definition of all genera. Therefore, the obtained results continued to demonstrate the phylogenetic utility of mitochondrial and nuclear barcodes, such as COI, histone H3 and ITS, for defining boundaries and phylogenetic relationships among scleractinian genera Arrigoni, Kitano, et al., 2014;Fukami et al., 2008;Kitahara et al., 2010). At the species level, we recovered only O. bennettae as a monophyletic species, whereas the other eight analysed species belonging to Astraeosmilia, Caulastraea and Oulophyllia were not resolved from a molecular perspective. ...
... The most likely explanation for the unresolved species relationships is that the four molecular markers chosen in this study were not variable enough to define species boundaries. The challenges of using relatively conserved markers to reconstruct evolutionary relationships have been discussed in several studies on reef corals (Arrigoni, Kitano, et al., 2014;Arrigoni, Richards, et al., 2014;Forsman et al., 2009;Huang, Benzoni, Arrigoni, et al., 2014;Prada et al., 2014;Terraneo et al., 2016Terraneo et al., , 2019. A lack of genetic differentiation can be the result of both slow evolution rate of coral mitochondrial genome and a lack of intragenomic variation of rDNA (Hellberg, 2006;Huang et al., 2008;Kitahara et al., 2016). ...
... The revised genus consists of four species that represent a wide degree of corallite organization, including cerioid, flabello-meandroid and phaceloid. More generally, as illustrated in previous studies (Arrigoni, Kitano, et al., 2014;Arrigoni et al., 2018;Arrigoni, Richards, et al., 2014;Benzoni et al., 2012;Budd et al., 2012;Forsman et al., 2009;Fukami et al., 2004;Huang et al., 2016;Huang, Benzoni, Arrigoni, et al., 2014;, our work clearly confirmed that colony growth form is regularly similar among lineages due to homoplasy. Taxonomic considerations based exclusively on this trait should be cautioned. ...
Modern systematics integrating molecular and morphological data has greatly improved our understanding of coral evolutionary relationships during the last two decades and led to a deeply revised taxonomy of the order Scleractinia. The family Merulinidae (Cnidaria: Scleractinia) was recently subjected to a series of revisions following this integrated approach but the phylogenetic affinities of several genera ascribed to it remain unknown. Here, we partially fill this gap through the study of 89 specimens belonging to all 10 valid species from four genera (Caulastraea, Erythrastrea, Oulophyllia and Dipsastraea) collected from 14 localities across the Indo‐Pacific realm. Four molecular loci (histone H3, COI, ITS and IGR) were sequenced, and a total of 44 skeletal morphological characters (macromorphology, micromorphology and microstructure) were analysed. Molecular phylogenetic analyses revealed that the phaceloid Caulastraea species are split into two distinct lineages. A species previously ascribed to the genus Dipsastraea, Dipsastraea maxima, is also recovered in one on these lineages. Furthermore, Erythrastrea is nested within Oulophyllia. The molecular reconstructions of evolutionary relationships are further corroborated by multiscale morphological evidence. To resolve the taxonomy of these genera, Astraeosmilia is resurrected to accommodate Astraeosmilia connata, Astraeosmilia curvata, Astraeosmilia tumida and Astraeosmilia maxima, with Caulastraea retaining Caulastraea furcata and Caulastraea echinulata. Based on the examination of type material, Erythrastrea flabellata is considered an objective synonym of Lobophyllia wellsi, which is transferred to Oulophyllia following the obtained morpho‐molecular results. This work further confirms that an integrated morpho‐molecular approach based on a rigorous phylogenetic framework is fundamental for an objective classification that reflects the evolutionary history of scleractinian corals.
... Such diversity is represented by a wide variety of growth forms (e.g., solitary and colonial), presence or absence of algal symbionts (i.e., zooxanthellate, azooxanthellate and apozooxanthellate), and an extensive geographic and bathymetric ranges, occurring from the tropics to polar regions at depths up to 2,165 m (Cairns, 2001). Although the family was recovered as monophyletic in the light of molecular data (Kitahara et al., 2010;Arrigoni et al., 2014), the generic evolutionary relationships within the family remains unclear, including several poly/paraphyletic genera (Arrigoni et al., 2014;Kitahara et al., 2016). ...
... Such diversity is represented by a wide variety of growth forms (e.g., solitary and colonial), presence or absence of algal symbionts (i.e., zooxanthellate, azooxanthellate and apozooxanthellate), and an extensive geographic and bathymetric ranges, occurring from the tropics to polar regions at depths up to 2,165 m (Cairns, 2001). Although the family was recovered as monophyletic in the light of molecular data (Kitahara et al., 2010;Arrigoni et al., 2014), the generic evolutionary relationships within the family remains unclear, including several poly/paraphyletic genera (Arrigoni et al., 2014;Kitahara et al., 2016). ...
... The classical taxonomy of scleractinian corals relies on skeletal morphological characters, but high intraspecific variation, convergence and homoplasy frequently challenge their identification, especially in shallow-water species (Todd, 2008). Among dendrophylliids, morphological characters used to reconstruct the evolutionary history of the group (i.e., corallum morphology, theca structure, calicular elements, and presence of zooxanthellae) do not seem to be sufficiently informative (Arrigoni et al., 2014). In addition, not all evolutionary changes resulting in speciation, such as changes in reproduction and ecology, are accompanied by detected morphological changes (Paz-García, García-de León & Balart, 2015;Gélin et al., 2017). ...
Atlantia is described as a new genus pertaining to the family Dendrophylliidae (Anthozoa, Scleractinia) based on specimens from Cape Verde, eastern Atlantic. This taxon was first recognized as Enallopsammia micranthus and later described as a new species, Tubastraea caboverdiana, which then changed the status of the genus Tubastraea as native to the Atlantic Ocean. Here, based on morphological and molecular analyses, we compare fresh material of T. caboverdiana to other dendrophylliid genera and describe it as a new genus named Atlantia in order to better accommodate this species. Evolutionary reconstruction based on two mitochondrial and one nuclear marker for 67 dendrophylliids and one poritid species recovered A. caboverdiana as an isolated clade not related to Tubastraea and more closely related to Dendrophyllia cornigera and Leptopsammia pruvoti. Atlantia differs from Tubastraea by having a phaceloid to dendroid growth form with new corallites budding at an acute angle from the theca of a parent corallite. The genus also has normally arranged septa (not Portualès Plan), poorly developed columella, and a shallow-water distribution all supporting the classification as a new genus. Our results corroborate the monophyly of the genus Tubastraea and reiterate the Atlantic non-indigenous status for the genus. In the light of the results presented herein, we recommend an extensive review of shallow-water dendrophylliids from the Eastern Atlantic.
... phylogram, constructed using a COI alignment of 601 bp, yielded three clades and a distinct branch with GoK Turbinaria sequence (Fig. 4). T. peltata, which ought to be moved to genus Duncanopsammia (Arrigoni et al., 2014), formed a distinct well-supported clade (I). The other clades (II and III) formed discrete groups and included some unidentified species. ...
... G20 from the GoK grouped separately (branch sister to Clades II-III). Clade I was composed of T. peltata, whereas Clade II was comprised of T. reniformis, T. horenensis, and two unidentified species from the south-west Pacific (Arrigoni et al., 2014). Clade III was formed of five species including two unidentified, two T. patula, two T. reniformis, and two T. mesenterina. ...
... Turbinaria (Oken, 1815) is an important shallowwater, reef-building genus in the Indo-Pacific. Species boundaries are typically obscured and troublesome (Arrigoni et al., 2014). Only two species of the genus Turbinaria are known from the GoK, i.e., T. peltata, T. mesenterina (Venkataraman, Satyanarayana, Alfred, & Wolstenholme, 2003). ...
Knowledge of extant biodiversity with accurate species boundaries is one of the crucial prerequisites for guiding conservation priorities in the face of global climate change. DNA taxonomy promises to provide a rapid and reliable tool for species delimitation of morphologically challenging taxa, such as reef-building corals. Despite harbouring diverse coral assemblages, molecular studies of hard corals occurring in the seas around India are lacking. The Gulf of Kutch (GoK), located in the north-western part of India, is one such region. Information on coral species inhabiting this unique ecosystem is limited to morphology, which is often highly variable and phenotypically plastic, obscuring species boundaries. Here, we present the first exploration of molecular divergence of hard corals of the GoK in order to identify evolutionarily distinct lineages. Nuclear ribosomal ITS and mitochondrial COI markers were sequenced for samples of dominant genera, Porites and Turbinaria for phylogenetic comparisons with available data from other ecosystems of the world. Five molecular species delimitation methods were applied to the datasets and their performance was evaluated. Our analyses clearly suggest the occurrence of unique genotypes of both these genera in the GoK, unequivocally discerned by all the five methods as well as microskeletal features. This first integrative assessment provides implications for the phylogeny of these genera and identifies previously unrecognized scleractinian species hidden in the GoK ecoregion.
... Scleractinian corals are an important group of organisms responsible for creating the framework of reefs and exerting important controls on global climate and the marine environment (Dishon et al., 2020). The evolutionary history of Scleractinia has long been tackled through: 1) traditional systematics based on an analysis of the macro scale skeletal characters (Cairns, 2001) and 2) molecular phylogenetics (Arrigoni et al., 2014). The incongruence between traditional and molecular systematics has stimulated the search for new fine-scale micromorphological and microstructural characters, both in the skeleton and soft tissue (Arrigoni et al., 2014;Terrón-Sigler and López-González, 2005). ...
... The evolutionary history of Scleractinia has long been tackled through: 1) traditional systematics based on an analysis of the macro scale skeletal characters (Cairns, 2001) and 2) molecular phylogenetics (Arrigoni et al., 2014). The incongruence between traditional and molecular systematics has stimulated the search for new fine-scale micromorphological and microstructural characters, both in the skeleton and soft tissue (Arrigoni et al., 2014;Terrón-Sigler and López-González, 2005). ...
The diversity in the skeletal features of coral species is an outcome of their evolution, distribution and habitat. Here, we explored, from macro- to nano-scale, the skeletal structural and compositional characteristics of three coral species belonging to the genus Balanophyllia having different trophic strategies. The goal is to address whether the onset of mixotrophy influenced the skeletal features of B. elegans, B. regia, and B. europaea. The macroscale data suggest that the presence of symbiotic algae in B. europaea can lead to a surplus of energy input that increases its growth rate and skeletal bulk density, leading to larger and denser corals compared to the azooxanthellate ones, B. regia and B. elegans. The symbiosis would also explain the higher intra-skeletal organic matrix (OM) content, which is constituted by macromolecules promoting the calcification, in B. europaea compared to the azooxanthellate species. The characterization of the soluble OM also revealed differences between B. europaea and the azooxanthellate species, which may be linked to diverse macromolecular machineries responsible for skeletal biosynthesis and final morphology. Differently, the crystallographic features were homogenous among species, suggesting that the basic building blocks of skeletons remained a conserved trait in these related species, regardless of the trophic strategy. These results show changes in skeletal phenotype that could be triggered by the onset of mixotrophy, as a consequence of the symbiotic association, displaying remarkable plasticity of coral skeletons which repeatedly allowed this coral group to adapt to a range of changing environments throughout its geological history.
... In fact, Campoy and colleagues 16 used four markers (18S rDNA, 28S rDNA, 16S rDNA and cox1) and 513 scleractinian coral species from almost all extant families and hypothesized that the first scleractinian would have been azooxanthellate and solitary. Nonetheless, symbiosis with zooxanthellae was widespread in Triassic corals 65 and there is some degree of disagreement about it being lost and reappearing a few times 64,66 or being gained only once during scleractinian evolution 16 . In contrast, it appears that coloniality was the first one to be gained and there is an agreement that it was lost and gained more than once 16,64 and even the presence of multiple mouths in one polyp seems to be a labile trait in some families of this order as well (e.g. ...
... In contrast, it appears that coloniality was the first one to be gained and there is an agreement that it was lost and gained more than once 16,64 and even the presence of multiple mouths in one polyp seems to be a labile trait in some families of this order as well (e.g. Dendrophylliidae 66 and Fungiidae 67,68 ). ...
Abstract Evolutionary reconstructions of scleractinian corals have a discrepant proportion of zooxanthellate reef-building species in relation to their azooxanthellate deep-sea counterparts. In particular, the earliest diverging “Basal” lineage remains poorly studied compared to “Robust” and “Complex” corals. The lack of data from corals other than reef-building species impairs a broader understanding of scleractinian evolution. Here, based on complete mitogenomes, the early onset of azooxanthellate corals is explored focusing on one of the most morphologically distinct families, Micrabaciidae. Sequenced on both Illumina and Sanger platforms, mitogenomes of four micrabaciids range from 19,048 to 19,542 bp and have gene content and order similar to the majority of scleractinians. Phylogenies containing all mitochondrial genes confirm the monophyly of Micrabaciidae as a sister group to the rest of Scleractinia. This topology not only corroborates the hypothesis of a solitary and azooxanthellate ancestor for the order, but also agrees with the unique skeletal microstructure previously found in the family. Moreover, the early-diverging position of micrabaciids followed by gardineriids reinforces the previously observed macromorphological similarities between micrabaciids and Corallimorpharia as well as its microstructural differences with Gardineriidae. The fact that both families share features with family Kilbuchophylliidae ultimately points towards a Middle Ordovician origin for Scleractinia.
... The genus Astroides is monospecific. Distinct microstructural features and 28S rRNA sequences 41,42 have revealed that A. calycularis, and species of Balanophyllia and Tubastraea form a monophyletic group 41 , highlighting the special phylogenetic position occupied by the orange coral within the Dendrophylliidae. ...
... Large polyps may generally offer better opportunities for capturing large prey 48 , including sea slugs 49 , especially in azooxanthellate species that depend exclusively on food intake for their nutrition, which is in fact a common feature among the Dendrophylliidae 38 . Thus, the possible advantage of having many (relatively) small polyps, in a colonial azooxanthellate species such as A. calycularis remains elusive 42 . However, recent evidence suggests that A. calycularis preys on large gelatinous plankton using a protocooperative strategy involving polyps of several colonies 50 . ...
Abstract Shallow-water marine organisms are among the first to suffer from combined effects of natural and anthropogenic drivers. The orange coral Astroides calycularis is a shallow-water bioconstructor species endemic to the Mediterranean Sea. Although raising conservation interest, also given its special position within the Dendrophylliidae, information about the threats to its health is scant. We investigated the health status of A. calycularis at five locations in northwestern Sicily along a gradient of cumulative human impact and the most probable origin of the threats to this species, including anthropogenic land-based and sea-based threats. Cumulative human impact appeared inversely related to the performance of A. calycularis at population, colony, and polyp levels. Sea-based human impacts appeared among the most likely causes of the variation observed. The reduction in polyp length can limit the reproductive performance of A. calycularis, while the decrease of percent cover and colony area is expected to impair its peculiar feeding behaviour by limiting the exploitable dimensional range of prey and, ultimately, reef functioning. This endangered habitat-forming species appeared susceptible to anthropogenic pressures, suggesting the need to re-assess its vulnerability status. Creating microprotected areas with specific restrictions to sea-based human impacts could be the best practice preserve these bioconstructions.
... Corallite morphology often aligns with genetics in many genera compared to corallum morphology [28]. Linear and geometric morphometrics have linked genomics with micromorphology across families, genera, and species [4,23,29,30]. The widely studied Pocillopora genus has shown incongruence between corallum morphology and genetic lineage identification [24,31,32], while micromorphological characters and genotypes down to the species level seems to be more congruent [6,33,34]. ...
Integrating multiple lines of evidence that support molecular taxonomy analysis has proven to be a robust method for species delimitation in scleractinian corals. However, morphology often conflicts with genetic approaches due to high phenotypic plasticity and convergence. Understanding morphological variation among species is crucial to studying coral distribution, life history, ecology, and evolution. Here, we present an application of Random Forest models for coral species identification based on morphological annotation of the corallum and corallites. We show that the integration of molecular and morphological trait analysis can be improved using machine learning. Morphological traits were documented for Porites and Pocillopora coral species that were collected and genotyped through genome-wide, genetical hierarchical clustering, and coalescence analyses for the Tara Pacific Expedition. While Porites only included three tentative species, most Pocillopora species were accounted by included specimens from the western Indian Ocean, tropical Southwestern Pacific, and southeast Polynesia. Two Random Forest models per genus were trained on the morphological annotations using the genetic lineage labels. One model was developed for in-situ image identification and used corallum traits measured from in-situ photographs. Another model for integrative species identification combined corallum and corallite data measured on scanning electron micrographs. Random Forest models outperformed traditional dimension reduction methods like PCA and FAMD followed by k-means and hierarchical clustering by classifying the correct genetic lineage despite morphological clusters overlapping. This machine learning approach is reproducible, cost-effective, and accessible, reducing the need for taxonomic expertise. It can complement molecular and phylogenetic studies and support image identification, highlighting its potential to advance a coral integrative taxonomy workflow.
... At Be'hau, pyrosomes were spotted "stuck" onto two individual corals of two different species: Hydnophora cf. pilosa and Duncanopsammia peltata (Arrigoni et al., 2014;Kelley, 2022). There was considerable extension of mesenterial filaments of H. pilosa (Figure 1b) which are used to digest food inside or outside of the coral mouth within a polyp. ...
... To date there are thirteen species assigned in three genera, Petrarca Fowler, 1889 (10 species), Introcornia Grygier, 1983 (two species) and the monotypic Zibrowia Grygier, 1985. They infect different species of azooxanthellate and zooxanthellate scleractinian corals of the family Dendrophylliidae, which occur in shallow to deep waters (see Cairns 2001;Arrigoni et al. 2014;Mehrothra et al. 2023). Normally petrarcids live in pairs inside a chamber in a single spongy gall without an aperture (Kolbasov et al. 2023a). ...
Zibrowia is a little-known genus of ascothoracidan endoparasites that live in the gastral cavity of solitary dendrophylliid corals. Before this study, all known specimens of Zibrowia were assigned to a single species, Z. auriculata , based on traditional morphological characters, although they were found in different locations and different hosts . The present study is based on an integrative approach and examines the morphological and molecular divergence of Zibrowia collected in Tubastraea corals in Taiwan and reveals three new species, Zibrowia mucronata sp. nov., Zibrowia caudata sp. nov., and Zibrowia trifurcata sp. nov. These three species are diagnosed based on the morphology of the carapace, the number of paired thoracopods and the abdomen structures. Based on sequence divergence in COI and the results obtained from Automatic Barcode Gap Discovery (ABGD), automatic partitioning analysis (ASAP), Poisson tree processes (PTP) model and Generalized Mixed Yule Coalescent (GMYC) methods, the samples of Zibrowia collected in Taiwan were assigned to four groups, corresponding to the three newly identified Zibrowia species and one that is undescribed, Zibrowia sp. This suggests that Zibrowia is a complex of cryptic species and that its hidden diversity in the Indo-Pacific should be further explored using an integrative taxonomy approach.
... In regard to the molecular work, we used the most common method of barcoding [4][5][6][7][8]. However, we agree that it would increase the accuracy and robustness of species identification if multiple markers, including mitochondrial COI gene, 16S rRNA, and nuclear ribosomal internal transcribed spacer (ITS) regions can be used together [8][9][10][11][12][13][14][15][16][17]. In practice, the results of our barcoding matched the conclusions reached using traditional morphologybased identification. ...
We appreciate the comments made by Hendawitharana et al [...]
... The term 'apo-zooxanthellate' 14 was presented to describe corals that are temporarily free of zooxanthellae for a variety of reasons (also referred to as 'aposymbiotic'). 'Apozooxanthellate' has since been applied to corals www.nature.com/scientificreports/ that exhibit a facultatively symbiotic relationship with zooxanthellate 36,37 . However, more recent literature 15 has highlighted that facultative symbiosis exists on a spectrum across high to low Symbiodiniaceae densities which is largely influenced by surrounding environmental conditions (such as light, irradiance and temperature), regardless of developmental stage. ...
Globally tropical Scleractinian corals have been a focal point for discussions on the impact of a changing climate on marine ecosystems and biodiversity. Research into tropical Scleractinian corals, particularly the role and breakdown of photoendosymbiosis in response to warming, has been prolific in recent decades. However, research into their subtropical, temperate, cold- and deep-water counterparts, whose number is dominated by corals without photoendosymbiosis, has not been as prolific. Approximately 50% of Scleractinian corals (> 700 species) do not maintain photoendosymbiosis and as such, do not rely upon the products of photosynthesis for homeostasis. Some species also have variable partnerships with photendosymbionts depending on life history and ecological niche. Here we undertake a systematic map of literature on Scleractinian corals without, or with variable, photoendosymbiosis. In doing so we identify 482 publications spanning 5 decades. In mapping research effort, we find publications have been sporadic over time, predominately focusing on a limited number of species, with greater research effort directed towards deep-water species. We find only 141 species have been studied, with approximately 30% of the total identified research effort directed toward a single species, Desmophyllum pertusum, highlighting significant knowledge gaps into Scleractinian diversity. We find similar limitations to studied locations, with 78 identified from the global data, of which only few represent most research outputs. We also identified inconsistencies with terminology used to describe Scleractinia without photoendosymbiosis, likely contributing to difficulties in accounting for their role and contribution to marine ecosystems. We propose that the terminology requires re-evaluation to allow further systematic assessment of literature, and to ensure it’s consistent with changes implemented for photoendosymbiotic corals. Finally, we find that knowledge gaps identified over 20 years ago are still present for most aphotoendosymbiotic Scleractinian species, and we show data deficiencies remain regarding their function, biodiversity and the impacts of anthropogenic stressors.
... Additional photographs were taken in situ and ex situ for specimens or associations deemed to be of particular interest. Corals were identified in situ based on corallite structure, septal structure (where visible/possible) and growth form, among other features, with identifications being aided by relevant taxonomic literature (i.e., Hoeksema 1989;Veron 2000;Cairns 2001;Arrigoni et al. 2014;Mehrotra et al. 2023). The exception was with regard to the species Porites lutea Milne Edwards & Haime, 1851 and P. lobata Dana, 1846, which were not always distinguishable in situ and thus were grouped together in an effort to again provide emphasis on surveying a greater number of corals in situ. ...
Recent years have seen a rapid increase in the study of coral-associated gastropods. In particular, the description of several new species in conjunction with their host specificity or dietary variability, has raised questions pertaining to their impact on reef health. These corallivores have been labelled as both ‘parasite’ and ‘predator’ by different studies, due to the tendency of some species to entirely consume their ‘host’ corals. Here we present new findings of corallivory and parasitism based on surveys conducted on the reefs of Koh Tao, Gulf of Thailand. A total of 6566 corals were assessed for their tendency to host gastropods of the nudibranch genus Phestilla and the caenogastropod family Epitoniidae. Thirteen gastropod species were found to be associated with 20 scleractinian coral species, including six that do not match the original description of previously known taxa. Herein we describe one of them, the first nudibranch proven to be associated with corals of the scleractinian genus Acropora and discuss conservation implications of these coral/gastropod relationships. Additionally, we explore the complex topic of defining these relationships as parasitic versus predatory and the merits of using these labels to better understand the ecology of these relationships.
... The phylogeny obtained with mitochondrial sequences was not well-resolved, with several nodes lacking support, and several genera did not appear monophyletic. This lack of monophyly of genera in the Dendrophylliidae family has already been observed with two mitochondrial and one nuclear markers (Arrigoni et al., 2014). Nevertheless, our results also underline the need to go further than mitochondrial sequences to work on species delimitation in this family. ...
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. Abstract The deep-sea corals Dendrophyllia ramea and Dendrophyllia cornigera occur in Mediterranean and Atlantic waters. Both species are found in different environmental conditions, and they can colonize hard and soft substrates. These species then display an important ecological plasticity along with morphological plasticity. Nevertheless, there is a large knowledge gap on the genetic characteristics of the two species, including on the relationships between them and the possibility of cryptic species along their range. The recent discovery of Dendrophyllia populations off Cyprus in the eastern Mediterranean Sea raised new questions in this context. These corals were related to D. ramea but had some morphological
... The phylogeny obtained with mitochondrial sequences was not well-resolved, with several nodes lacking support, and several genera did not appear monophyletic. This lack of monophyly of genera in the Dendrophylliidae family has already been observed with two mitochondrial and one nuclear markers (Arrigoni et al., 2014). Nevertheless, our results also underline the need to go further than mitochondrial sequences to work on species delimitation in this family. ...
The deep‐sea corals Dendrophyllia ramea and Dendrophyllia cornigera occur in Mediterranean and Atlantic waters. Both species are found in different environmental conditions, and they can colonize hard and soft substrates. These species then display an important ecological plasticity along with morphological plasticity. Nevertheless, there is a large knowledge gap on the genetic characteristics of the two species, including on the relationships between them and the possibility of cryptic species along their range. The recent discovery of Dendrophyllia populations off Cyprus in the eastern Mediterranean Sea raised new questions in this context. These corals were related to D. ramea but had some morphological differences with other known populations of this species. Here, we study the specific status of Dendrophyllia corals from Cyprus on the basis of morphology and genetics. The genetic data are interpreted by comparison with the same analysis performed on two Caryophyllia species. Both morphological and genetic data confirm that corals found off Cyprus belong to the D. ramea species. We further tested the speciation scenario using transcriptome data: the results indicate an absence of current gene flow between D. ramea and D. cornigera and that the divergence occurred more than 3 million years ago. We discuss the possible historical and ecological factors which may have shaped speciation in these species.
... Therefore, it is possible that the azooxanthellate nature of N. kamurai colonies described originally from Zamami may have been due to bleaching at that location, instead of being the natural condition of Nanipora. This would, in turn, suggest that Nanipora is among the few known aragonite-forming corals that can be apozooxanthellate, with the symbiont-host relationship apparently being more facultative than obligate (Schuhmacher and Zibrowius 1985; Hoeksema and Best 1991; Arrigoni et al. 2014). ...
Nanipora Miyazaki & Reimer, 2015 is a recently described monotypic octocoral genus belonging to the family Helioporidae (class Octocorallia). Nanipora kamurai Miyazaki & Reimer, 2015 was formally described from shallow coral reefs around Zamami Island, within Kerama-shoto National Park, in Okinawa Prefecture, southern Japan. To date, Nanipora has been reported from two other locations in Japan: N. aff. kamurai from a shallow inner lagoon at Iriomotejima Island, and Nanipora cf. kamurai from the coral reef surrounding a shallow CO2 vent at Iotorishima Island, both in Okinawa Prefecture. Additionally, Nanipora cf. kamurai has been reported from three locations outside Japan: in shallow seagrass meadows at Dongsha Atoll in the South China Sea, on coral reefs at Koh Tao in Thailand and from a reef in Toboso, central Philippines. Finally, N. kamurai has been detected in environmental DNA samples from the Rowley Shoals off northwestern Australia. As a ‘living fossil’ and also apparently common in the low pH environment of Iotorishima I., a clearer understanding of the distribution of the genus should aid in better understanding of its ecology. Here, we report three new additional records from the Ryukyu Archipelago where Nanipora colonies were found, resulting in ten total records of Nanipora. Molecular phylogenetic analyses utilizing cytochrome oxidase subunit I (COI), mitochondrial mismatch repair protein (mtMutS), and the internal transcribed spacer region (ITS) sequences of specimens from two of these new locations combined with additional sequences from previously collected specimens from Dongsha, Iotorishima, and Iriomotejima showed evidence of three closely related groups within Nanipora, warranting future investigations into the species diversity of this genus.
... Each specimen was identified to species level according to skeleton morphology. The following taxonomic references were used: Cairns (1984Cairns ( , 1989Cairns ( , 1991Cairns ( , 1994Cairns ( , 1995Cairns ( , 1999Cairns ( , 2000Cairns ( , 2001Cairns ( , 2004, Cairns and Parker (1992), Cairns and Zibrowius (1997), Cairns and Kitahara (2012), Cairns and Polonio (2013), Araya et al. (2016), Arrigoni et al. (2014), Altuna (2013), Altuna and Ríos (2014), Cordeiro et al. (2012), Song (2014, 2016), Lam et al. (2008), Qurban et al. (2020), Kitahara (2007), Kitahara andCairns (2008, 2021), Kitahara et al. (2010), Tachikawa (2005) and Zibrowius and Gili (1990). Taxonomic names were checked against the World Register of Marine Species (WoRMS, http://www.marinespecies. ...
Scleractinian cold-water corals (CWCs) are one of the most important habitat engineers of the deep sea. Although the South China Sea (SCS) abuts the biodiversity center of scleractinian CWCs in the western Pacific, only a few sporadic records are available. We discovered new CWC sites by means of trawl sampling and video observation along the continental shelf of the northwestern SCS. All trawled scleractinian CWC specimens were identified to species level according to skeleton morphology and structure. The living CWCs and associated fauna recorded in the video were -identified to a higher level of classification. Scleractinian corals were identified to genus level, while non-scleractinian CWCs were identified to family level and given general names such as gorgonian corals, bamboo corals and black corals. Associated benthic dwellers were divided into major categories. A total of 28 scleractinian CWC species were identified to 7 families, 15 genera, and 1 additional subgenus. Among them, 13 species were colonial, including important habitat-forming species in the genera Eguchipsammia, Dendrophyllia and Cladopsammia. Non-scleractinian CWCs were identified to 7 families, including 4 families gorgonian corals, 1 family bamboo corals, and 2 families black corals. Gorgonian corals were the most abundant non-scleractinian CWCs in this region. Meanwhile, starfish, sea anemones, fish, gastropods, echinoderms, and other associated benthic fauna were recorded in the CWC habitats, with starfish belonging to the order Brisingida being most common. New scleractinian CWC assemblages were discovered along the continental seabed mounds in the northwestern SCS. This study highlights the remarkable diversity of cold-water scleractinian corals in the whole SCS, and shows the potential widespread distribution and conservation prospect of CWC habitats in this region.
... Approximately a decade later, Fukami et al. (2004Fukami et al. ( , 2008 used nuclear and mitochondrial gene trees to demonstrate a deep evolutionary divergence between Pacific and Atlantic lineages despite extensive similarities of macromorphological characteristics for many taxa, such as Faviidae Milne Edwards & Haime, 1857, Lobophylliidae Dai &Horng, 2009, andMerulinidae Milne Edwards &Haime, 1857. The integration of molecular and morphological data has led to many other significant changes across the scleractinian tree of life in the last two decades, including the designation of new families, the elevation of genus and species names out of synonymy, and the description of new species (Benzoni et al., 2007(Benzoni et al., , 2010(Benzoni et al., , 2012a(Benzoni et al., , 2012bWallace et al., 2007;Kitahara et al., 2010a;Huang et al., 2011Huang et al., , 2014aHuang et al., , 2014bHuang et al., , 2016Gittenberger et al., 2011;Arrigoni et al., 2012Arrigoni et al., , 2014aArrigoni et al., , 2014bArrigoni et al., , 2014cArrigoni et al., , 2014dArrigoni et al., , 2021Kitano et al., 2014;Luzon et al., 2017;Juszkiewicz et al., 2022). ...
A well-supported evolutionary tree representing most major lineages of scleractinian corals is in sight with the development and application of phylogenomic approaches. Specifically, hybrid-capture techniques are shedding light on the evolution and systematics of corals. Here, we reconstructed a broad phylogeny of Scleractinia to test previous phylogenetic hypotheses inferred from a few molecular markers, in particular, the relationships among major scleractinian families and genera, and to identify clades that require further research. We analysed 449 nuclear loci from 422 corals, comprising 266 species spanning 26 families, combining data across whole genomes, transcriptomes, hybrid capture and low-coverage sequencing to reconstruct the largest phylogenomic tree of scleractinians to date. Due to the large number of loci and data completeness (<38% missing data), node supports were high across shallow and deep nodes with incongruences observed in only a few shallow nodes. The "Robust" and "Complex" clades were recovered unequivocally, and our analyses confirmed that Micrabaciidae Vaughan, 1905 is sister to the "Robust" clade, transforming our understanding of the "Basal" clade. Several families remain polyphyletic in our phylogeny, including Deltocyathiidae Kitahara, Cairns, Stolarski & Miller, 2012, Caryophylliidae Dana, 1846, and Coscinaraeidae Benzoni, Arrigoni, Stefani & Stolarski, 2012, and we hereby formally proposed the family name Pachyseridae Benzoni & Hoeksema to accommodate Pachyseris Milne Edwards & Haime, 1849, which is phylogenetically distinct from Agariciidae Gray, 1847. Results also revealed species misidentifications and inconsistencies within morphologically complex clades, such as Acropora Oken, 1815 and Platygyra Ehrenberg, 1834, underscoring the need for reference skeletal material and topotypes, as well as the importance of detailed taxonomic work. The approach and findings here provide much promise for further stabilising the topology of the scleractinian tree of life and advancing our understanding of coral evolution.
... That said, as the taxonomy of these free-living corals is uncertain and primarily based on macromorphological differences (Hoeksema and Best 1991), it is not possible to know if this species represents one or a suite of species. Recent phylogenies have highlighted incongruities between morphology-based taxonomies and molecular data (Arrigoni et al. 2014). However, research on the taxonomy of the genus Heteropsammia is lacking. ...
Halimeda bioherms on the Northern Great Barrier Reef (GBR) extend for over 6000 km 2. To explore the ecological and biogeographical importance of these bioherms was one of the aims of a recent voyage on the Research Vessel (RV) Investigator. Through the use of underwater images and habitat sampling, we found populations of Heteropsammia cochlea (Spengler, 1781) living in the bioherms. The scleractinian coral genus Heteropsammia (Dendrophylliidae) is a group of solitary, apozooxanthellate, single-polyp corals with a widespread distribution in tropical and subtropical regions. Populations of H. cochlea were observed with individuals dispersed on open-sand habitat and among patches of Halimeda at 30-40 m water depth in mean densities of 89 and 29 corals per m 2 , respectively. Fluorescence microscopy was used to assess the presence of zooxanthellae, indicating that they are actively photosynthesising at these depths. These are the first observations of H. cochlea in association with the Halimeda bioherms on the Northern GBR.
... retrieved over time (per year) in relation to the known range where the study was carried out. The line represents the ratio of number of documents which pertain to the native relative to nonnative ranges (cumulative over time)in 2021 and 2022(Yiu et al. 2021;Yiu and Qiu 2022); suspended combination of T. aurea and new genus Australopsammia aurea (Quoy and Gaimard 1833) (Rowlett 2020); a new species T. caboverdiana(Ocaña et al. 2015) then superseded combination Atlantia caboverdiana(Ocaña and Brito 2015) (Capel et al. 2020b); cryptic species(Figueroa et al. 2019;Yiu and Qiu 2022); phylogeny reconstruction(Arrigoni et al. 2014)]. Regarding Tubastraea spp. ...
Invasive species stimulate science through problem-oriented research but only a small portion of studies have discussed the impacts of biological invasions upon the science itself. Three of the ten currently recognized species of the coral genus Tubastraea are invasive and have attracted substantial research attention. Using a bibliographic survey and bibliometric approach we synthesized knowledge to examine if invasion events lead to an increase and intensification of research not mirrored in the native range. More than twice as many studies of the genus were performed in the nonnative ranges than native, most being original research recently published in the conventional literature. Brazil and the United States of America (Gulf of Mexico) (nonnative range) were most studied with oil and gas platforms the main (49%) focus of pathway and vector research. Ecological processes such as recruitment, survivorship, larval settlement, and population abundance and structure, were proportionally more studied in nonnative ranges, as were competitive interactions. This synthesis of the set of knowledge that is available about Tubastraea spp. demonstrates that invasion biology is a highly pragmatic science and as the genus has expanded its range through the world the scientific community has increasingly focused its attention on the invasion which has provided science, management and stakeholders with a wide body of information on many basic and applied aspects of the biology and ecology of the species.
... The yellow coral Dendrophyllia cornigera (Lamarck, 1816) is a colonial scleractinian characterized by sparse irregular branching, bright yellow colour of the coenenchyma and size up to 40 cm (Zibrowius, 1980;Fourt et al., 2017). Like all the other members of the family Dendrophylliidae, whose monophyly has been confirmed by Arrigoni et al. (2014), this species is characterized by porous walls and a peculiar arrangement of septa in triangles (the so-called Pourtalès plan) (Cairns, 2001). In the Mediterranean Sea, this family accounts for eight species, four of which inhabit deeper waters, namely Balanophyllia (Balanophyllia) cellulosa Duncan, 1873, D. cornigera, Dendrophyllia ramea characterization of the peculiar D. cornigera population of the Mantice Shoal, with information on spatial and bathymetrical extension, substrate type, inclination, density and size-class frequency distribution. ...
... It is apparent that D. axifuga is confused with other species of the family Dendrophyllidae. Its large polyps resemble those of Duncanopsammia peltata Esper, 1790, Eguchipsammia fistula (Alcock, 1902), and Tubastraea micranthus Ehrenberg, 1834, but these species have different growth forms [2,12,14]. The present study may therefore help readers to recognize the species more easily in the field, especially on murky reefs. ...
Duncanopsammia axifuga (Scleractinia: Dendrophylliidae) is reported for the first time from Indonesia. A population was found in 5-m deep, murky water on a sediment-rich, inshore reef at Bird’s Head Peninsula, West Papua. Some corals were attached to dead coral and others were loose fragments living on sediment. One attached specimen was observed to be damaged as a result of direct contact with an adjacent Goniopora coral. Free-living specimens on sand are more likely able to escape competition for space. These observations may help to better understand the northernmost range limit and the natural environment of D. axifuga, a species that is popular in the international aquarium trade, but has not been studied very well in the field.
... Experiments were conducted on non-symbiotic corals belonging to the Tubastraea genus. Corals belonging to this genus possess poorly defined taxonomic features and several unidentified morphotypes that severely challenge species identification 128 Micro-dissection, RNA isolation and sequencing from Tubastraea spp. Three biological replicates of Tubastraea spp. ...
In hermatypic scleractinian corals, photosynthetic fixation of CO 2 and the production of CaCO 3 are intimately linked due to their symbiotic relationship with dinoflagellates of the Symbiodiniaceae family. This makes it difficult to study ion transport mechanisms involved in the different pathways. In contrast, most ahermatypic scleractinian corals do not share this symbiotic relationship and thus offer an advantage when studying the ion transport mechanisms involved in the calcification process. Despite this advantage, non-symbiotic scleractinian corals have been systematically neglected in calcification studies, resulting in a lack of data especially at the molecular level. Here, we combined a tissue micro-dissection technique and RNA-sequencing to identify calcification-related ion transporters, and other candidates, in the ahermatypic non-symbiotic scleractinian coral Tubastraea spp. Our results show that Tubastraea spp. possesses several calcification-related candidates previously identified in symbiotic scleractinian corals (such as SLC4-γ, AMT-1like, CARP, etc.). Furthermore, we identify and describe a role in scleractinian calcification for several ion transporter candidates (such as SLC13, -16, -23, etc.) identified for the first time in this study. Taken together, our results provide not only insights about the molecular mechanisms underlying non-symbiotic scleractinian calcification, but also valuable tools for the development of biotechnological solutions to better control the extreme invasiveness of corals belonging to this particular genus.
... Although the ecological role of Dendrophylliidae is well known, our current knowledge about the phylogenetic relationships of the family remains scarce. Most taxa in fact have been predominately investigated morphologically or with few genes (Arrigoni et al. 2014;Kitahara et al. 2016;Capel et al. 2020). Reduced-representation genome approaches, such as RAD sequencing, are shedding light into coral evolution by providing a fast and efficient way to reconstruct mitochondrial genomes (hereafter mitogenome) (Forsman et al. 2017;Terraneo et al. 2018aTerraneo et al. , 2018b. ...
The scleractinian coral family Dendrophylliidae is a major component of shallow and deep-water coral ecosystems worldwide, but our knowledge on the evolutionary history of the family remains scarce. Here, we used ezRAD coupled with Illumina sequencing technology and reconstructed the complete mitochondrial genome of Dendrophyllia minuscula (GenBank accession number OL634845), from mesophotic depths in the Red Sea NEOM area. The mitochondrial genome of D. minuscula consisted of 19,054 bp, organized in 13 protein-coding genes, 2 rRNA genes, and 2 tRNA genes, in agreement with the Scleractinia typical mitogenome organization. This complete mitochondrial genome contributes toward a better knowledge of mesophotic and deep-water coral diversity and evolutionary history.
... Molecular systematics resolved these biogeographically separated elkhorn corals as highly divergent lineages and distinct species . Molecular data has also helped identify evolutionary convergence in at least five other scleractinian coral families (Dendrophyllidae: Arrigoni et al., 2014;Fungiidae: Benzoni et al., 2012;Gittenberger et al., 2011;and Mussidae: Merulinidae, and Lobophylliidae, Budd et al., 2012;Fukami et al., 2004). ...
Scleractinian corals are a diverse group of ecologically important yet highly threatened marine invertebrates, which can be challenging to identify to the species level. An influx of molecular studies has transformed scleractinian systematics, highlighting that cryptic species may be more common than previously understood. In this study, we test the hypothesis that Plesiastrea versipora (Lamarck, 1816), a species currently considered to occur throughout the Indo-Pacific in tropical, sub-tropical and temperate waters, is a single species. Molecular and morphological analyses were conducted on 80 samples collected from 31 sites spanning the majority of the species putative range and twelve mitogenomes were assembled to identify informative regions for phylogenetic reconstruction. Congruent genetic data across three gene regions supports the existence of two monophyletic clades aligning with distinct tropical and temperate provenances. Multivariate macromorphological analyses based on 13 corallite characters provided additional support for the phylogeographic split, with the number of septa and corallite density varying across this biogeographic divide. Furthermore, micromorphological and microstructural analyses identified that the temperate representatives typically develop sub-cerioid corallites with sparse or absent coenosteal features and smooth septal faces. In contrast, tropical representatives typically develop plocoid corallites separated by a porous dissepimental coenosteum and have granulated septal faces. These data suggest that at least two species exist within the genus Plesiastrea Milne Edwards & Haime, 1848. Based on examination of type material, we retain the name Plesiastrea versipora (Lamarck, 1816) for the temperate representatives of the genus and resurrect the name Plesiastrea peroni Milne Edwards & Haime, 1857 for the tropical members. This study highlights how broadly distributed hard coral taxa still need careful re-examination through an integrated systematics approach to better understand their phylogeographic patterns. Furthermore, it demonstrates the utility of integrating micro-, macro-morphological and genetic datasets, and the importance of type specimens when dealing with taxonomic revisions of scleractinian taxa.
... A total of 3%, N = 27 of H. cochlea showed even more than two polyps. Budding is a feature common in this F I G U R E 1 Map showing (a) the location of the study area in the Zanzibar Archipelago; and (b) the study sites (black squares indicate study sites)species and is usually developed by elongation and later bipartition of the main corallite(Arrigoni et al., 2014). ...
Marine symbioses are integral to the persistence of ecosystem functioning in coral reefs. Solitary corals of the species Heteropsammia cochlea and Heterocyathus aequicostatus have been observed to live in symbiosis with the sipunculan worm Aspidosiphon muelleri muelleri, which inhabits a cavity within the coral, in Zanzibar (Tanzania). The symbiosis of these photosymbiotic corals enables the coral holobiont to move, in fine to coarse unconsolidated substrata, a process termed as “walking.” This allows the coral to escape sediment cover in turbid conditions which is crucial for these light‐dependent species. An additional commensalistic symbiosis of this coral‐worm holobiont is found between the Aspidosiphon worm and the cryptoendolithic bivalve Jousseaumiella sp., which resides within the cavity of the coral skeleton. To understand the morphological alterations caused by these symbioses, interspecific relationships, with respect to the carbonate structures between these three organisms, are documented using high‐resolution imaging techniques (scanning electron microscopy and µCT scanning). Documenting multi‐layered symbioses can shed light on how morphological plasticity interacts with environmental conditions to contribute to species persistence. The photosymbiotic solitary corals Heteropsammia cochlea and Heterocyathus aequicostatus live in symbiosis with the sipunculid worm Aspidosiphon muelleri muelleri, and the cryptoendolithic bivalve Jousseaumiella sp., which reside within the cavity of the coral skeleton. The symbiosis enables the coral holobiont to escape sediment cover in turbid conditions. High‐resolution imaging reveals morphological alterations caused by these symbioses, and allows to better understand the interspecific relationships.
... Based on a literature comparison, the South African Rhizopsammia verrilli differs from the previously reported Indo-Pacific representatives by having four complete cycles instead of five, the last incomplete. Striking similarities between R. verrilli and R. wettsteini Scheel & Pillai, 1983 have been highlighted (Arrigoni et al 2014), however specimens of the latter have not been examined and thus a comparison is not detailed herein. Specimens reported here are new records for the South African region, but not for the southwest Indian Ocean, as this R. verrilli has been recorded off Mozambique by MacNae and Kalk (1958). ...
Globally, South Africa ranks in the top five countries regarding marine species richness per unit area. Given the high diversity, it is not surprising that many invertebrate taxa in the region are poorly characterised. The South African azooxanthellate Scleractinia (Anthozoa) is one such taxonomic group, and was last reviewed by Boshoff in 1980. Although more recent regional publications have reported on some species, there has not been a faunistic review that accounts for the country’s species diversity since then. Moreover, numerous unidentified specimens representing more than three decades of sampling effort have accumulated. In this study the authors update the state of knowledge of South African azooxanthellate coral species. Specimens, particularly those within the extensive collections of the Iziko South African and Smithsonian museums, were morphologically examined and identified. Other data considered included historic data represented as imagery data, associated species data from recent research surveys, and the scientific literature. To date, the study has increased the total number of known species from 77 to 108 across eleven families, 28 new South African records, and three are new species with one new genus.
... Our analysis supports several subsequent losses of coloniality in scleractinians but no secondary gains. This result is also likely to change with increased taxon sampling, as molecular phylogenetic analyses of scleractinian families that include colonial and solitary forms have found evidence for both evolutionary transitions (Gittenberger et al. 2011;Arrigoni et al. 2014). ...
Anthozoan cnidarians (corals and sea anemones) include some of the world's most important foundation species, capable of building massive reef complexes that support entire ecosystems. Although previous molecular phylogenetic analyses have revealed widespread homoplasy of the morphological characters traditionally used to define orders and families of anthozoans, analyses using mitochondrial genes or rDNA have failed to resolve many key nodes in the phylogeny. With a fully resolved, time-calibrated phylogeny for 234 species constructed from hundreds of ultraconserved elements and exon loci, we explore the evolutionary origins of the major clades of Anthozoa and some of their salient morphological features. The phylogeny supports reciprocally monophyletic Hexacorallia and Octocorallia, with Ceriantharia as the earliest diverging hexacorals; two reciprocally monophyletic clades of Octocorallia; and monophyly of all hexacoral orders with the exception of the enigmatic sea anemone Relicanthus daphneae. Divergence dating analyses place Anthozoa in the Cryogenian to Tonian periods (648–894 Ma), older than has been suggested by previous studies. Ancestral state reconstructions indicate that the ancestral anthozoan was a solitary polyp that had bilateral symmetry and lacked a skeleton.
Colonial growth forms and the ability to precipitate calcium carbonate evolved in the Ediacaran (578 Ma) and Cambrian (503 Ma) respectively; these hallmarks of reef-building species have subsequently arisen multiple times independently in different orders. Anthozoans formed associations with photosymbionts by the Devonian (383 Ma), and photosymbioses have been gained and lost repeatedly in all orders. Together, these results have profound implications for interpretation of the Precambrian environment and the early evolution of metazoans.
... Our analysis supports several subsequent losses of coloniality in scleractinians but no secondary gains. This result is also likely to change with increased taxon sampling, as molecular phylogenetic analyses of scleractinian families that include colonial and solitary forms have found evidence for both evolutionary transitions (Gittenberger et al. 2011;Arrigoni et al. 2014). ...
Anthozoan cnidarians (corals and sea anemones) include some of the world's most important foundation species, capable of building massive reef complexes that support entire ecosystems. Although previous molecular phylogenetic analyses have revealed widespread homoplasy of the morphological characters traditionally used to define orders and families of anthozoans, analyses using mitochondrial genes or rDNA have failed to resolve many key nodes in the phylogeny. With a fully resolved, time-calibrated phylogeny for 234 species constructed from hundreds of ultraconserved elements and exon loci, we explore the evolutionary origins of the major clades of Anthozoa and some of their salient morphological features. The phylogeny supports reciprocally monophyletic Hexacorallia and Octocorallia, with Ceriantharia as the earliest diverging hexacorals; two reciprocally monophyletic clades of Octocorallia; and monophyly of all hexacoral orders with the exception of the enigmatic sea anemone Relicanthus daphneae. Divergence dating analyses place Anthozoa in the Cryogenian to Tonian periods (648–894 Ma), older than has been suggested by previous studies. Ancestral state reconstructions indicate that the ancestral anthozoan was a solitary polyp that had bilateral symmetry and lacked a skeleton. Colonial growth forms and the ability to precipitate calcium carbonate evolved in the Ediacaran (578 Ma) and Cambrian (503 Ma) respectively; these hallmarks of reef-building species have subsequently arisen multiple times independently in different orders. Anthozoans formed associations with photosymbionts by the Devonian (383 Ma), and photosymbioses have been gained and lost repeatedly in all orders. Together, these results have profound implications for interpretation of the Precambrian environment and the early evolution of metazoans.
... More than 5 replications of the process from extraction to amplification were conducted to ensure that the final sequencing accuracy is more than 99%. The QIAGEN Multiplex PCR Kit (Qiagen, Hilden, Germany) was used to perform the polymerized chain reaction for the amplification of mitochondrial region 16S 39 and IGR 40 . The PCR cycling parameters used are as follows: initial 95 °C denaturation for 15 min. ...
Abstract This paper reports a deep-water coral framework (a single colonial bush or a larger bioconstruction of coral covering the sea bottom), formed entirely by the scleractinian coral Eguchipsammia fistula (Alcock, 1902) (Dendrophylliidae), in the northern Red Sea waters of Saudi Arabia at a depth of about 640 m. The framework consists of mostly live corals with a total area of about 10 m2 and the length of the individual coral branches range from 12 to 30 cm. Although E. fistula is ubiquitous, this discovery is the second record of a framework formed by this species and the first discovery of a large living reef in the Red Sea. The results of the genetic study indicate the potential existence of a genetic variation of E. fistula in the Red Sea. This discovery implies that the Red Sea has favorable habitats for framework-forming DWC species and highlights the need for conducting more systematic surveys for understanding their distribution, abundance, and ecology.
... In dead polyps (Fig. 2b), septa of the new species show a bifurcating pattern according to the Pourtal es plan (Cairns 1994), which does not occur in Tubastraea (Fig. 2c). The septal pattern and the presence of stolons indicate that this species belongs to either the genus Cladopsammia or Rhizopsammia, which are both phylogenetically closely related to Tubastraea (Cairns 2001, Arrigoni et al. 2014. Genetic information on Atlantic Cladopsammia and Rhizopsammia is currently not available, but a preliminary molecular analysis based on the mitochondrial marker cytochrome c oxidase subunit I (COI) revealed that the species found on Curac ßao is very closely related to both Cladopsammia gracilis (Milne Edwards & Haime, 1848) and Rhizopsammia wettsteini (Scheer & Pillai, 1983) from the Red Sea (A.-F. ...
In contrast with a general decline of Caribbean reef corals, a previously rare sun coral is increasing in abundance within shallow coral communities on Curac ßao. This azooxanthellate scleractinian was identified as Cladopsammia manuelensis, which has an amphi-Atlantic distribution. Over the last decade , C. manuelensis has increased abundance along the leeward coast of Curac ßao (southern Caribbean) between depths of 4 and 30 m. This species was initially not noticed because it resembles the invasive coral Tubastraea coccinea, which was introduced to Curac ßao from the Indo-Pacific around 1940. However, in contrast to T. coccinea, C. manuelensis was previously only present on deeper reef sections (>70 m) of Caribbean reefs. Our observations illustrate how the sudden increase in abundance of a previously unnoticed, apparently cryptogenic species could result from natural dynamics on present-day reefs, but also could easily be mistaken for an invasive species. The finding that deep reef sections can harbor species capable of colonizing shallower reef zones highlights the importance of thorough inventories of reef communities across large depth ranges, which can help us to discriminate between range increases of native species and the arrival of invasives.
... Dendrophylliidae : Arrigoni et al. (2014a) and Cairns (2001). ...
Volume 2 presents the last part of coral studies carried out by late Hans Ditlev (HD). We have revised the nomenclature to be in accordance with WoRMS. In case of recent changes, we have also shown the names applied by Hans Ditlev (HD id as). We have not changed his descriptions but we have supplemented texts where HD had photos but no text. Such places are marked by an asterisk and source ofcitation. The following taxa are illustrated: Agariciidae (5 genera, 33 sp.), Caryophylliidae (1 genus, 1 sp.), Coscinaraeidae (3 genera, 6 sp.), Dendrophylliidae (5 genera, 17 sp.), Diploastreidae (1 genus, 1 sp.), Fungiidae (15 genera, 108 sp.), Lobophylliidae (9 genera, 32 sp.), Merulinidae (21 genera, 108 sp.), Mussidae, (1 genus, 1 sp.), Psammocoridae (1 genus, 7 sp.), Siderastreidae (2 genera, 2 sp.), Familia incertae sedis (5 genera, 15 sp.). Technical terms are explained and the original identification keys by HD are rewritten and expanded considering the many changes coral taxonomy has gone through in recent years. An overview of coral literature is compiled and listed by author, year and title of publication. A substantial part ofthe publications can be downloaded from the Internet.
... Phylogenetic reconstructions and species delimitation of scleractinian corals have long been hampered by a disagreement between genetic data and colony-level morphology [43][44][45][46][47]. This challenge is particularly difficult among genera in which colony morphology is known to be highly variable, such as the Hawaiian Montipora. ...
Background:
Evolutionary patterns of scleractinian (stony) corals are difficult to infer given the existence of few diagnostic characters and pervasive phenotypic plasticity. A previous study of Hawaiian Montipora (Scleractinia: Acroporidae) based on five partial mitochondrial and two nuclear genes revealed the existence of a species complex, grouping one of the rarest known species (M. dilatata, which is listed as Endangered by the International Union for Conservation of Nature - IUCN) with widespread corals of very different colony growth forms (M. flabellata and M. cf. turgescens). These previous results could result from a lack of resolution due to a limited number of markers, compositional heterogeneity or reflect biological processes such as incomplete lineage sorting (ILS) or introgression.
Results:
All 13 mitochondrial protein-coding genes from 55 scleractinians (14 lineages from this study) were used to evaluate if a recent origin of the M. dilatata species complex or rate heterogeneity could be compromising phylogenetic inference. Rate heterogeneity detected in the mitochondrial data set seems to have no significant impacts on the phylogenies but clearly affects age estimates. Dating analyses show different estimations for the speciation of M. dilatata species complex depending on whether taking compositional heterogeneity into account (0.8 [0.05-2.6] Myr) or assuming rate homogeneity (0.4 [0.14-0.75] Myr). Genomic data also provided evidence of introgression among all analysed samples of the complex. RADseq data indicated that M. capitata colour morphs may have a genetic basis.
Conclusions:
Despite the volume of data (over 60,000 SNPs), phylogenetic relationships within the M. dilatata species complex remain unresolved most likely due to a recent origin and ongoing introgression. Species delimitation with genomic data is not concordant with the current taxonomy, which does not reflect the true diversity of this group. Nominal species within the complex are either undergoing a speciation process or represent ecomorphs exhibiting phenotypic polymorphisms.
... The other Mediterranean species included in the dataset, P. pulchellus, was sister to Polycyathus muellerae, a shallow-water coral occurring also in the Mediterranean Sea. Although the majority of shallow-water scleractinian families are polyphyletic, Arrigoni et al. (2014) confirmed the monophyly of Dendrophylliidae using molecular phylogeny, micromorphology and skeleton microstructure. In their study, sequences of five Mediterranean species were included, two of which Dendrophyllia cornigera and L. pruvoti occur in deep waters, although the latter is of predominant shallow-water occurrence. ...
Within the Mediterranean basin there are 82 species of deep-sea corals belonging to six orders of the phylum Cnidaria (Antipatharia, Scleractinia, Zoantharia, Alcyonacea, Pennatulacea and Anthoathecata), with the Alcyonacea (40) and the Scleractinia (25) being the most speciose. Thirteen species have a pronounced habitat-building ability at depths >200 m. Remarkable sites characterised by rich coral frameworks and gardens have been found in biodiversity surveys during the last years, revealing that some species are more abundant than previously thought. However, in terms of species richness, the Mediterranean deep-sea coral fauna is less diverse when compared with the nearby Atlantic areas. This discrepancy is probably in part due to unfavourable environmental conditions of the deep Mediterranean Sea, and to differences in sampling efforts between both areas. In this respect, considerable efforts have been recently done in terms of deep-sea fauna inventories. Nevertheless, updates made to the Mediterranean inventory of deep-sea corals since the beginning of the twenty-first century are few except for the octocorals. Therefore, ten species were included to the Mediterranean inventory, among which two have been newly described. The species concerned belong to the orders Scleractinia (1), Pennatulacea (1) and Alcyonacea (8).
Scleractinian corals play important roles in the maintenance and restoration of coral systems. However, the evolutionary relationships among species remain unclear, mostly due to the limitations of traditional coral classifications because of their ecophenotypic variation and morphological plasticity. Thus, here we aimed to reconstruct the phylogenetic relationships of corals through single- and multi-gene analyses based on 116 colonies (14 families and 49 species) from Weizhou Island, China, and five molecular markers (CO1, 16S rRNA, 12S rRNA, H3, and ITS). The results reveal four cryptic species (Platygyra pini, Platygyra verweyi, Psammocora nierstraszi, and Coscinaraea columna). In single-gene analyses, mitochondrial genes can classify taxa at the family but not genus level, and vice versa for nuclear genes. Species are divided into complex and robust corals based on multi-gene analysis. Within robust corals, Merulinidae (Group XVII) is classified into eight subclades, and Dipsastraea, Favites, and Goniastrea are polyphyletic. Complex corals comprise the monophyletic Acroporidae (VI), Agariciidae (VII), Euphylliidae (V), Porites (III), and Dendrophylliidae (II). Notably, Turbinaria peltata is highly divergent from its congeners and clusters. Multi-gene analysis proved to be more accurate than single-gene analysis in elucidating phylogenetic relationships among corals. This study enhances our understanding of the diversity, evolution, and conservation of corals from Weizhou Island.
Taxonomic classification of the scleractinian corals underwent major revisions from 2012 to 2014, focusing on the former families Mussidae and Faviidae. Since then, changes in scientific names due to the taxonomic revisions of many other corals have been also reported every year. Especially, Rowlett (2020) reported taxonomic revisions of many families and genera of corals. Thus, in the current situation where the taxonomic classification is changing rapidly, coral researchers need to update the scientific names they use. However, it is difficult for researchers who are not deeply involved in taxonomy to spend time on this task. Therefore, in this article, we introduce the main scleractinian corals at the species rank and the higher taxonomic groups that have undergone the changes of the scientific names due to taxonomic revisions since 2016.
The construction and maintenance of coral reefs primarily depends on the calcification of corals, which produce a rigid skeleton made of CaCO3 in the crystalline form of aragonite. Most reef-building corals live in symbiosis with photosynthetic dinoflagellates of the Symbiodiniaceae family, which provide the coral host with energy and nutrients. Given their ecological importance, much progress has been made in identifying key elements of the mechanisms underlying coral calcification. Nevertheless, there are still significant gaps in our understanding. Foremost is the characterization of ion transporters, used by the coral calcifying cells to promote calcification. To contribute to this lack of knowledge, targeted and broad approaches, coupled with molecular and bioinformatics tools, have been used throughout this thesis. Using the targeted approach, ion transporter proteins, previously reported to be involved in calcification of other calcifying species, have been identified for the first time in the genome and transcriptome of the symbiotic coral Stylophora pistillata. Whereas, using a broad approach, novel candidate genes for roles in calcification have been identified in the non-symbiotic coral Tubastraea spp. Overall, both approaches contributed to a better understanding of the ion transporting mechanisms used by the coral calcifying cells to promote calcification in this ecologically important group of marine animals.
In the current study, scleractinian corals from the Albian (uppermost Lower Cretaceous; 112.6–99.7 Ma) including 337 species (280 taxa assigned to species; 57 taxa kept in open nomenclature) from 147 genera (six of which include subgenera) belonging to 42 families (two of which include subfamilies; and incertae sedis) are evaluated and revised. Two new species (Apoplacophyllia asiatica, new species and Trigerastraea sikharulidzeae, new species) are described and two lectotypes are designated. Some specimens are illustrated for the first time, and new material (from Austria) is presented. The coral material includes records from 30 regions in Africa, the Americas, the Arctic, Asia, Australasia, and Europe. The most extensive records of Albian corals are from tropical/subtropical and arid areas, including the U.S.A., Mexico, Greece, France, and Spain. Over three-quarters of the Albian taxa belong to morphological forms having little to no hermatypic character (sensu Coates & Oliver), including species of the cerioid-plocoid group (genera: 36.7%; species: 38.5%), solitary taxa (genera: 26.5%; species: 28%), and branching forms (genera: 26.5%; 39 species ¼ 11.5%). The coral faunas of the Albian are dominated by corals of ‘‘modern’’ microstructural groups sensu Roniewicz & Morycowa (76 genera ¼ 51.7%; 169 species ¼ 50.1%). Compared
to the lowermost Cretaceous (Berriasian), which showed that 91% of the species and 83% of the genera belonged to previously established microstructural groups, the Lower Cretaceous ends with ‘‘modern’’ groups having become dominant. During the lower and middle Albian, the vast majority of taxa belonged to colonial forms (both 74%). A shift took place during the upper Albian, significantly increasing the number of solitary species to over 40% of the Albian fauna (42.9%). Throughout the Albian, the most diverse coral assemblages include non-reefal faunas, suggesting that, in contrast to, e.g., the Barremian–Aptian time period, reefal developments were less crucial for coral recruitment during this time. This study of the Albian fauna was used as the basis for synthesizing classical taxonomic works with modern microstructural data and recent DNA analyses in order to propose both a modified taxonomic framework and a working hypothetical phylogenetic tree for 41 scleractinian families occurring in the fossil record. [Note: all 8 supplementary Appendices are now available]
Scleractinian corals provide habitats for a broad variety of cryptofauna, which in turn may contribute to the overall functioning of coral symbiomes. Among these invertebrates, hydrozoans belonging to the genus Zanclea represent an increasingly known and ecologically important group of coral symbionts. In this study, we analysed 321 Zanclea colonies associated with 31 coral genera collected from 11 localities across the Indo-Pacific and Caribbean regions, and used a multi-disciplinary approach to shed light on the evolution and biogeography of the group. Overall, we found high genetic diversity of hydrozoans that spans nine clades corresponding to cryptic or pseudo-cryptic species. All but two clades are associated with one or two coral genera belonging to the Complex clade, whereas the remaining ones are generalists associated with both Complex and Robust corals. Despite the observed specificity patterns, no congruence between Zanclea and coral phylogenies was observed, suggesting a lack of coevolutionary events. Most Zanclea clades have a wide distribution across the Indo-Pacific, including a generalist group extending also into the Caribbean, while two host-specific clades are possibly found exclusively in the Red Sea, confirming the importance of this peripheral region as an endemicity hotspot. Ancestral state reconstruction suggests that the most recent common ancestor of all extant coral-associated Zanclea was a specialist species with a perisarc, occurring in what is now known as the Indo-Pacific. Ultimately, a mixture of geography- and host-related diversification processes is likely responsible for the observed enigmatic phylogenetic structure of coral-associated Zanclea.
As coral populations decline worldwide in the face of ongoing environmental change, documenting their distribution, diversity and conservation status is now more imperative than ever. Accurate delimitation and identification of species is a critical first step. This task, however, is not trivial as morphological variation and slowly evolving molecular markers confound species identification. New approaches to species delimitation in corals are needed to overcome these challenges. Here, we test whether target enrichment of ultraconserved elements (UCEs) and exons can be used for delimiting species boundaries and population structure within species of corals by focusing on two octocoral genera, Alcyonium and Sinularia, as exemplary case studies. We designed an updated bait set (29,181 baits) to target‐capture 3,023 UCE and exon loci, recovering a mean of 1,910 ± 168 SD per sample with a mean length of 1,055 ± 208 bp. Similar numbers of loci were recovered from Sinularia (1,946 ± 227 SD) and Alcyonium (1,863 ± 177 SD). Species‐level phylogenies were highly supported for both genera. Clustering methods based on filtered single nucleotide polymorphisms delimited species and populations that are congruent with previous allozyme, DNA barcoding, reproductive and ecological data for Alcyonium, and offered further evidence of hybridization among species. For Sinularia, results were congruent with those obtained from a previous study using restriction site associated DNA sequencing. Both case studies demonstrate the utility of target‐enrichment of UCEs and exons to address a wide range of evolutionary and taxonomic questions across deep to shallow timescales in corals.
Corals have been attracting huge attention due to the impact of climate change and ocean acidification on reef formation and resilience. Nevertheless, some species like Tubastraea coccinea and T. tagusensis have been spreading very fast replacing the native ones which affect the local environment and decrease biodiversity of corals and other organisms associated with them. Despite some focal efforts to understand the biology of these organisms, they remain understudied at the molecular level. This knowledge gap hinders the development of cost-effective strategies for both conservation and management of invasive species. In this circumstance, it is expected that genome sequencing would provide powerful insights that could lead to better strategies for prevention, management, and control of this and other invasive species. Here, we present three genomes of Tubastraea spp. in one of the most comprehensive biological studies of corals, that includes flow cytometry, karyotyping, transcriptomics, genomics, and phylogeny. The genome of T. tagusensis is organized in 23 chromosomes pairs and has 1.1 Gb, the T. coccinea genome is organized in 22 chromosome pairs and has 806 Mb, and the Tubastraea sp. genome is organized in 21 chromosome pairs and has 795 Mb. The hybrid assembly of T. tagusensis using short and long-reads has a N50 of 227,978 bp, 7,996 contigs and high completeness estimated as 91.6% of BUSCO complete genes, of T. coccinea has a N50 of 66,396 bp, 17,214 contigs and 88.1% of completeness, and of Tubastraea sp. has a N50 of 82,672 bp, 12,922 contigs and also 88.1% of completeness. We inferred that almost half of the genome consists of repetitive elements, mostly interspersed repeats. We provide evidence for exclusive Scleractinia and Tubastraea gene content related to adhesion and immunity. The Tubastraea spp. genomes are a fundamental study which promises to provide insights not only about the genetic basis for the extreme invasiveness of this particular coral genus, but to understand the adaptation flaws of some reef corals in the face of anthropic-induced environmental disturbances. We expect the data generated in this study will foster the development of efficient technologies for the management of coral species, whether invasive or threatened.
Comparative lists of species’ extinction risk are increasingly being used to prioritise conservation resources. Extinction risk is most rigorously assessed using quantitative data on species’ population trajectories, but in the absence of such data, assessments often rely on qualitative estimates based on expert opinion of species abundances, distributions and threats. For example, one-third of coral species are classified as threatened and another third as near threatened on the IUCN Red List, despite a lack of data at the population level for the vast majority of species. Since many taxa show a strong correlation between species traits and extinction risk, an alternate approach is to identify traits associated with extinction in other groups and apply them to the taxon of interest. Here, we examine whether life-history traits associated with stress tolerance, fecundity and habitat specialisation are correlated with Red List conservation status in reef corals. We found no relationship between conservation status and life-history traits, suggesting that either traits identified as important predictors of extinction risk in other taxa are not important in corals, or that conservation status does not accurately reflect species’ relative extinction risk. Therefore, using global-scale extinction risk assessments to inform conservation of coral reefs presents a high risk of ‘silent extinctions’ of undescribed species. We argue that the conservation status for the vast majority of coral species should be ‘data deficient’ and is likely to remain so for the foreseeable future, and that the status and trends of coral populations can only be reliably assessed at relatively small scales.
Recent molecular phylogenetic analyses of scleractinian corals have resulted in the discovery of cryptic lineages. To understand species diversity in corals, these lineages need to be taxonomically defined. In Fungia fungites (Linnaeus, 1758) (Scleractinia, Fungiidae) is a species complex that conceals large phenotypic variation and a previously unrecognized genus the present study, we report the discovery of a distinct lineage obscured by the traditional morphological variation of Fungia fungites. This taxon exists as two distinct morphs: attached and unattached. Molecular phylogenetic analyses using mitochondrial COI and nuclear ITS markers as well as morphological comparisons were performed to clarify their phylogenetic relationships and taxonomic positions. Molecular data revealed that F. fungites consists of two genetically distinct clades (A and B). Clade A is sister to a lin-eage including Danafungia scruposa and Halomitra pileus, while clade B formed an independent lineage genetically distant from these three species. The two morphs were also found to be included in both clades, although the attached morph was predominantly found in clade A. Morphologically, both clades were statistically different in density of septal dentation, septal number, and septal teeth shape. These results indicate that F. fungites as presently recognized is actually a species complex including at least two species. After checking type specimens, we conclude that specimens in clade A represent true F. fungites with two morphs (unattached and attached) and that all of those in clade B represent an unknown species and ge-nus comprising an unattached morph with only one exception. These findings suggest that more unrecognized taxa with hitherto unnoticed morphological differences can be present among scleractinian corals.
Traditionally and for practical reasons, skeleton structure has been the main source of taxonomic characters
for scleractinian systematics, whereas information from soft tissues has been comparatively neglected. However, skeleton variability may leave species identification uncertain. The use of characters from soft tissues (e.g. polyp anatomy, cnidae size) is routine in the study of other (“soft”) hexacorallian orders. This contribution aims to determine whether cnidae characters are useful in taxonomic studies of scleractinians. The cnidae composition of two congeneric species—Balanophyllia europaea (Risso, 1826) and Balanophyllia regia Gosse, 1860—have been studied throughout a wide geographical area. The data obtained show consistent qualitative and quantitative differences between the two species. This study shows that the cnidae characters can be useful taxonomic criteria for distinguishing congeneric species.
Three Indonesian species of Heterocyathus and two of Heteropsammia are briefly diagnosed. Remarks are given on their synonymy, phenotypic variation, and ecology. All five species are found on soft substrata in the proximity of coral reefs and live in association with a sipunculan worm. This interspecific assocation is discussed with regard to whether it is mutualistic or parasitic.
An update of the phylogeny and biogeography of mushroom coral species belonging to Fungia (Pleuractis) is presented. Among the five species of this monophyletic group, one is described as new to science. This species, Fungia seychellensis spec, nov., was discovered during the Netherlands Seychelles Expedition (1992-1993) in the framework of the Netherlands Indian Ocean Programme 1990/1995.
The phylogenetic relationships of the Fungiidae, a family of predominantly free-living, zooxanthellate, reef corals, were studied by sequencing a part of the mitochondrial Cytochrome Oxidase I (COI) and the complete ribosomal Internal Transcribed Spacers (ITS) I & II of specimens from various locations in the Indo-West Pacific. Some sequences were retrieved by using fungiid-specific primers on DNA-extracts from parasitic gastropods living with these corals. The analyses were performed both including and excluding intraspecific variation to investigate the potential effect of saturation. Even though the present molecular phy-logeny reconstructions largely reflect those based on morphological characters, there are some distinct differences. Three major clades are distinguished, one of which consists of species with relatively long tentacles. The two other major clades cannot yet be clearly separated from each other morphologically. Several polyphyletic taxa were detected and some genera and species that previously were considered closely related to each other, appear not to be so. Proposed nomenclatorial changes include amongst others the upgrading of subgenera in Fungia to genus level. A few species moved from one genus to another. Among all Fungiidae, the loss of the ability to become free-living appears to have evolved independently as reversals in four separate clades, including two that were previously assumed to be sister groups. The evolution of corals with additional (secondary) mouths leading to polystomatous growth forms from corals with only a single primary mouth (monostomatous growth form) appears to have occurred independently ten times: seven times by extrastomatal budding and three times by intrastomatal budding. In two clades, Herpolitha and Polyphyllia, both mechanisms co-evolved. In general there is no clear relationship between the loss of a free-living phase and the evolution of multiple mouths.
A phylogenetically based comparative analysis of onshore-off-shore distribution patterns of mushroom coral species (Sclerac-tinia: Fungiidae) was made to reconstruct an evolutionary sce-nario for differentiation in fungiid shelf habitats. This phylo-ecological study integrates data on fungiid distribution patterns along environmental gradients on the Spermonde Shelf, SW Sulawesi, with a recently published phylogeny reconstruction of the Fungiidae. A mushroom coral fauna of 34 species was used to compare their distributions by use of 50-m 2 belt quadrats in transects (1) from the mainland to the shelf edge, (2) around reefs with regard to predominant wind directions, and (3) over bathymetrical reef zones. Species association ordinations were made for each of the four shelf zones using both abundance and incidence data to examine whether closely related species co-occurred. Some closely related species or even sister species appeared to show very similar distribution patterns and to co-exist in high abundances. These results indicate that there may not be community saturation and competitive exclusion among mushroom corals species, most of which are free-living. In re-constructions of fungiid habitat evolution, offshore reef slopes appear to be original (ancestral), whereas onshore habitats, shallow reef flats, and deep sandy reef bases seem to be derived. The latter is in contrast with an earlier hypothesis, in which deep sandy substrates were considered ancestral mushroom coral habitats.
Scleractinian corals are widely distributed in all oceans and at all bathymetric levels. Corals are among the most important bio-building organisms in marine ecosystems. The systematics of this hexacoral group is currently undergoing much change owing to studies that combine molecular analyses with morphological research on the calcareous skeletons. However, information from polyp anatomy has been widely ignored, and some aspects, such as the diversity and distribution of the cnidocysts, might help to obtain a better understanding of the relationships at different taxonomic levels. In this study, the cnidocysts of four species of the family Dendrophylliidae (Dendrophyllia ramea, D. cornigera, D. laboreli and Astroides calycularis) are analysed to evaluate the application of cnidae in phylogenetic analyses, and to complete our knowledge of cnidae composition (types, distribution and sizes) for these species. A discriminant analysis based on the cnidae of these species supports the usefulness of these structures. The obtained results indicate that additional morphological characters in scleractinian corals that may help to clarify their phylogenetic relationships can still be found.
The family Poritidae formerly included 6 genera: Alveopora, Goniopora, Machadoporites, Porites, Poritipora, and Stylaraea. Morphologically, the genera can be differentiated based on the number of tentacles, the number of septa and their arrangement, the length of the polyp column, and the diameter of the corallites. However, the phylogenetic relationships within and between the genera are unknown or contentious. On the one hand, Alveopora has been transferred to the Acroporidae recently because it was shown to be more closely related to this family than to the Poritidae by previous molecular studies. On the other hand, Goniopora is morphologically similar to 2 recently described genera, Machadoporites and Poritipora, particularly with regard to the number of septa (approximately 24), but they have not yet been investigated at the molecular level. In this study, we analyzed 93 samples from all 5 poritid genera and Alveopora using 2 genetic markers (the barcoding region of the mitochondrial COI and the ITS region of the nuclear rDNA) to investigate their phylogenetic relationships and to revise their taxonomy. The reconstructed molecular trees confirmed that Alveopora is genetically distant from all poritid genera but closely related to the family Acroporidae, whereas the other genera are genetically closely related. The molecular trees also revealed that Machadoporites and Poritipora were indistinguishable from Goniopora. However, Goniopora stutchburyi was genetically isolated from the other congeneric species and formed a sister group to Goniopora together with Porites and Stylaraea, thus suggesting that 24 septa could be an ancestral feature in the Poritidae. Based on these data, we move G. stutchburyi into a new genus, Bernardpora gen. nov., whereas Machadoporites and Poritipora are merged with Goniopora.
Seventy-four universal primers for characterizing the complete mitochondrial genomes of scleractinian corals (Cnidaria; Anthozoa). Zoological Studies 50(4): 513-524. Use of universal primers designed from a public DNA database can accelerate characterization of mitochondrial (mt) genomes for targeted taxa by polymerase chain reaction (PCR) amplification and direct DNA sequencing. This approach can obtain large amounts of mt information for phylogenetic inferences at lower costs and in less time. In this study, 88 primers were designed from 13 published scleractinian mt genomes, and these were tested on Euphyllia ancora, Galaxea fascicularis, Fungiacyathus stephanus, Porites okinawensis, Goniopora columna, Tubastraea coccinea, Pavona venosa, Oulastrea crispata, and Polycyathus sp., representing 7 families of complex and robust corals. Seventy-four of the 88 primers (84.1%) successfully amplified completed mt genomes of these 9 corals. Several unique features were identified, including a group I intron insertion in the cytochrome oxidase subunit I (COI) genes of Por. okinawensis, Gon. columna, T. coccinea, and F. stephanus and an extended length of the 3'-end of the COI gene of E. ancora. Preliminary tests using a subset of primers successfully obtained the COI 3'-end of Euphyllia representatives, and the resulting species phylogeny is in agreement with corallite characters and tentacle shapes. The universal primers provided herein effectively decoded scleractinian mt genomes, and can be used to reveal different levels of molecular phylogenetic inferences in scleractinian corals.
A CRITICAL CHECKLIST of the 54 species of ahcmlatypic Sclemclinia known from the Hawaiian Islands is given. Based on a collection of approximately 1.150 specimens from 186 stations. new records are documented for 42 of lhesc species. including 19 new records for the Hawaiian Islands. 8 of these being new species. A synonymy. discussion. and distribution arc given for each of the 42 species collected; lhose species new to the Hawaiian Islands arc illustrated. This new checklist of species shows the Hawaiian deep-water Scleraclinia to be an attenuated Indo-West Pacific fauna having a 48% endemic component. II 17% central-we!;1 Pacific component. a 15% Indo-West Pacific emnponcnt. and II 17% cosmopolitan compo-nent. Deep-water Scleractinia from two stations from Christmas Island (in the Line Islands) and one station off Johnston Atoll arc aho reponed.
During the last decade, knowledge of azooxanthellate corals in the Colombian Caribbean has increased through exploration campaigns by the Marine and Coastal Research Institute (INVEMAR). The distribution of 142 species of corals, including hard corals (Scleractinia 64 species), black corals (Antipatharia 18 species), and soft corals (Octocorallia 60 species) is assessed. Statistical analyses were performed to examine the coral species distribution through a geographic gradient (210 stations in 8 sectors) and a bathymetric range (10–520 m depth). Four principal patterns were observed: (1) northeastern distribution (46 species), (2) southwestern distribution (11 species), (3) association with azooxanthellate coral bioherms (37 species), and (4) widespread (44 species). In addition, 4 species were only found around the San Andres Archipelago (insular pattern). Two main oceanographic factors were identified to play a role in the northeast versus southwest coral fauna separation, La Guajira upwelling system and the Magdalena River influx. These patterns appear to be depth-related, since the separation between northeast and southwest was mainly shown by the shallow-water coral fauna, whereas most of the deep-water corals (>200 m depth) were widely distributed along the Colombian Caribbean coastline. These data were also analyzed from a conservation perspective in order to propose new strategies for the protection of the Colombian Caribbean coral fauna.
During daytime dives in July 2011 on the reefs of Kota Kinabalu (Sabah, Malaysia), large quantities of slow-moving salps (Tunicata: Thaliacea: Salpida) were observed. Some of these were seen to be caught and ingested by various mushroom corals (Fungiidae) and an anchor coral (Euphylliidae). The predators had complete salps (2–6 cm long) or partly digested salp remnants stuck inside their wide-open mouths. Salps that were observed landing on top of mushroom corals did not escape. They became captured by tentacles and were transported towards the opening coral mouths. To our knowledge, the present in situ observation is the first record of numerous salps being consumed by corals. All the observed predating coral species, either belonging to monostomatous or polystomatous species, possessed large mouths. The presence of multiple mouths enables mushroom corals to become larger than those with single mouths. Because a large polyp size facilitates the capture of food, it is advantageous for them to be polystomatous, especially when they possess a large mouth.
The zoanthid genus Sphenopus (Cnidaria: Anthozoa: Zoantharia), like many other brachycnemic zoanthids, is found in shallow subtropical and tropical waters, but is uniquely unitary (solitary, monostomatous), azooxanthellate, and free-living. With sparse knowledge of its phylogenetic position, this study examines the phylogenetic position of Sphenopus within the family Sphenopidae utilizing specimens from southern Taiwan and Brunei collected in 1999-2011, and furthermore analyzes the evolution of its unique character set via ancestral state reconstruction analyses. Phylogenetic analyses surprisingly show Sphenopus to be phylogenetically positioned within the genus Palythoa, which is colonial (polystomatous), zooxanthellate, and attached to solid substrate. Ancestral state reconstruction strongly indicates that the unique characters of Sphenopus have evolved recently within Palythoa and only in the Sphenopus lineage. These results indicate that zoanthid body plans can evolve with rapidity, as in some other marine invertebrates, and that the traditional definitions of zoanthid genera may need reexamination.
Submarine canyons are known as one of the seafloor morphological features where living cold-water coral (CWC) communities develop in the Mediterranean Sea. We investigated the CWC community of the two westernmost submarine canyons of the Gulf of Lions canyon system: the Cap de Creus Canyon (CCC) and Lacaze-Duthiers Canyon (LDC). Coral associations have been studied through video material recorded by means of a manned submersible and a remotely operated vehicle. Video transects have been conducted and analyzed in order to obtain information on (1) coral bathymetric distribution and density patterns, (2) size structure of coral populations, and (3) coral colony position with respect to the substrate. Madrepora oculata was the most abundant CWC in both canyons, while Lophelia pertusa and Dendrophyllia cornigera mostly occurred as isolated colonies or in small patches. An important exception was detected in a vertical cliff in LDC where a large L. pertusa framework was documented. This is the first record of such an extended L. pertusa framework in the Mediterranean Sea. In both canyons coral populations were dominated by medium and large colonies, but the frequent presence of small-sized colonies also indicate active recruitment. The predominant coral orientation (90° and 135°) is probably driven by the current regime as well as by the sediment load transported by the current flows. In general, no clear differences were observed in the abundance and in the size structure of the CWC populations between CCC and LDC, despite large differences in particulate matter between canyons.
Traditionally and for practical reasons, skeleton structure has been the main source of taxonomic characters for scleractinian systematics, whereas information from soft tissues has been comparatively neglected. However, skeleton variability may leave species identification uncertain. The use of characters from soft tissues (e.g. polyp anatomy, cnidae size) is routine in the study of other (“soft”) hexacorallian orders. This contribution aims to determine whether cnidae characters are useful in taxonomic studies of scleractinians. The cnidae composition of two congeneric species—Balanophyllia europaea (Risso, 1826) and Balanophyllia regia Gosse, 1860 have been studied throughout a wide geographical area. The data obtained show consistent qualitative and quantitative differences between the two species. This study shows that the cnidae characters can be useful taxonomic criteria for distinguishing congeneric species.
The focus of this paper is to provide an overview of historical and modern accounts of scleractinian evolutionary relationships and classification. Scleractinian evolutionary relationships proposed in the 19th and the beginning of the 20th centuries were based mainly on skeletal data. More in-depth observations of the coral skeleton showed that the gross-morphology could be highly confusing. Profound differences in microstructural and microarchitectural characters of e.g., Mesozoic microsolenine, pachythecaliine, stylophylline, stylinine, and rhipidogyrine corals compared with nominotypic representatives of higher-rank units in which they were classified suggest their separate (?subordinal) taxonomic status. Recent application of molecular techniques resulted in hypotheses of evolutionary relationships that differed from traditional ones. The emergence of new and promising research methods such as high-resolution morphometrics, analysis of biochemical skeletal data, and refined microstructural observations may still increase resolution of the “skeletal” approach. Achieving a more reliable and comprehensive scheme of evolutionary relationships and classification framework for the Scleractinia will require close cooperation between coral biologists, ecologists, geologists, geochemists, and paleontologists.
Bleaching was studied in populations of phylogenetically closely related species (n = 21) of mushroom corals (Scleractinia:Fungiidae) around Pari Island (Java Sea) during a period of excessive seawater warming in 1983. The interspecific variation in the proportions of affected individuals was significant. Spatial variation in the degree of bleaching among fungiid assemblages depended much on relative species abundances. Mushroom corals in relatively stagnant water of lagoons and on the inner reef flat showed little bleaching. Many of the outer reef mushroom corals at less-than-or-equal-to 9 m depth were affected, but only a few at greater depths (greater-than-or-equal-to 15 m). In most affected fungiids, the bleached part was pale (associated with pigment loss) instead of white (assumedly caused by zooxanthellae expulsion). The difference between the proportions of paled and whitened corals was not clearly depth-related, but most probably species-related. Most bleached fungiids were affected over their whole upper surface, whereas others showed a mosaic pattern. Entire bleaching was most common at depths < 6 m and partial bleaching at 9 m. One species with a predominantly shallow distribution (mainly less-than-or-equal-to 9 m) showed a significant majority of entirely bleached individuals. The smallest mushroom corals (empty set(max) less-than-or-equal-to 5 cm) on the outer reef, usually in sheltered positions, and the largest ones (empty set(max) > 20 cm), usually occurring deep, were the least affected. The latter may have escaped bleaching by recurrent downward migration.
The Fungiidae are mushroom corals that live in sublittoral habitats in the tropical Indo-Pacific. Their habitats are part of coral reefs or other marine substrata, which usually can be found in the proximity of the reefs. In the present taxonomic revision, the family is divided into 11 genera; one of which, Fungia, is subdivided into seven subgenera. A total of 40 species is described and figured, three of which are new to science. One species is renamed. The stratigraphic distribution is given for all the species recorded in fossil state. A tentative phylogenetic reconstruction down to the species level is given. The cladogram that is provided should be considered a working hypothesis and not a sound basis for a completely revised classification and nomenclature of the Fungiidae. For each species the presently known geographic range is mapped. The pattern of species richness in the Indo-Pacific is compared with that of some other taxa and discussed with respect to their distributional patterns. The ranges of the Fungiidae are analyzed with the use of approaches from both historical and ecological biogeography.
The phylogenetic relationships of the scleractinian genus Psammocora with the other genera traditionally included in the family Siderastreidae and some Fungiidae are assessed based on combined skeletal and molecular data. P. explanulata differs from the other examined congeneric species (P. contigua, P. digitata, P. nierstraszi, P. profundacella, P. superficialis, and P. stellata) in possessing interstomatous septa between adult corallites, costae, and in having continuous buttress-like structures joining septal faces (i.e., fulturae) which typically occur in fungiids. These characters are shared with Coscinaraea wellsi but not with the remainder of the examined siderastreids (the congeneric C. columna, and Anomastraea irregularis, Horastrea indica, Pseudosiderastrea tayamai, Siderastrea savignyana) whose septa are interconnected by typical synapticulae. Most of the examined species form septa with distinct transverse groups of centers of calcification, a biomineralization pattern typical of the Robusta clade. The observations on skeletal structures corroborate the results of the ITS2 and 5.8S molecular phylogeny. C. wellsi and P. explanulata are phylogenetically very close to each other and show closer genetic affinity with the examined Fungiidae (Halomitra pileus, Herpolitha limax, Fungia paumotensis, and Podabacia crustacea) than with the other species in the genera Psammocora and Coscinaraea, or with any other siderastreid. Our results show that neither Psammocora nor Coscinaraea are monophyletic genera. The high genetic distances between the species of Siderastreidae, especially between Pseudosiderastrea tayamai and Siderastrea savignyana on one side and the other genera on the other, suggest a deep divergence in the phylogenetic structure of the family.
Until coral molecular phylogenies were published, the genus Plesiastrea was traditionally part of the family Faviidae and considered by several authors to be closely related to the genus Montastraea. However, genetic data has shown that Plesiastrea versipora, the genus type species, is evolutionarily distinct within the Robust clade of the Scleractinia and does not belong to the large clade grouping most representatives of the families Faviidae, including Montastraea, Mussidae, Merulinidae. Trachyphylliidae, and Pectiniidae. Instead, P. versipora is closely related to non reef-dwelling taxa currently ascribed to the Oculinidae (Cyathelia axillaris) and Caryophylliidae (Trochocyathus efateensis). However, no discussion on the morphologic features of P. versipora compared to other taxa has been published yet. Moreover, no information is available about the phylogenetic placement of Plesiastrea devantieri, the only other species in the genus. The phylogeny of both Plesiastrea species was addressed through molecular analyses (COI and rDNA) and morphological analysis. Morphological differences between the two species included number of septa, cycles of vertical structures in front of the septa and septal micromorphology. On the basis of these data and nuclear and mitochondrial markers. P. devantieri belongs to the Faviidae-Merulinidae-Pectiniidae-Trachyphylliidae clade (Clade XVII sensu Fukami et al., 2008) and is most closely related to Goniastrea aspera and G. palauensis. The type species of the genus Goniastrea, G. retiformis, however, is not closely related to either G. aspera and G. palauensis, or to P. devantieri. Taxonomic implications of these findings and morphologic affinities between the two species and closely related taxa are discussed.
The scleractinian species Psammocora explanulata and Coscinaraea wellsi were originally classified in the family Siderastreidae, but in a recent morpho-molecular study it appeared that they are more closely related to each other and to the Fungiidae than to any siderastreid taxon. A subsequent morpho-molecular study of the Fungiidae provided new insights regarding the phylogenetic relationships within that family. In the present study existing molecular data sets of both families were analyzed jointly with those of new specimens and sequences of P. explanulata and C. wellsi. The results indicate that both species actually belong to the Cycloseris clade within the family Fungiidae. A reappraisal of their morphologic characters based on museum specimens and recently collected material substantiate the molecular results. Consequently, they are renamed Cycloseris explanulata and C. wellsi. They are polystomatous and encrusting like C. mokai, another species recently added to the genus, whereas all Cycloseris species were initially thought to be monostomatous and free-living. In the light of the new findings, the taxonomy and distribution data of C. explanulata and C. wellsi have been updated and revised. Finally, the ecological implications of the evolutionary history of the three encrusting polystomatous Cycloseris species and their free-living monostomatous congeners are discussed.
Dactylotrochus cervicornis (= Tridacophyllia cervicornis Moseley, 1881), which occurs in Indo-Pacific waters between 73 and 852 m, was originally described as an astraeid but was later transferred to the Caryophylliidae. Assumed to be solitary, this species has no stolons and only one elongated fossa, and is unique among azooxanthellate scleractinians in often displaying extremely long thecal extensions that are septate and digitiform. Based on both molecular phylogenetic analyses (partial mitochondrial CO1 and 16S rDNA, and partial nuclear 28S rDNA) and morphological characteristics, we propose the transfer of D. cervicornis from the Caryophylliidae to the Agariciidae, making it the first extant representative of the latter family that is solitary and from deep water (azooxanthellate). The basal position of D. cervicornis within the agariciids implied by our analyses strengthens the case for inclusion of fossil species that were solitary, such as Trochoseris, in this family and suggests that the ancestor of this scleractinian family, extant members of which are predominantly colonial and zooxanthellate, may have been solitary and azooxanthellate.
The monotypic genus Craterastrea was assigned to the family Siderastreidae owing to the similarity of its septal micromorphology to that of Coscinaraea. Subsequently, it was synonymized with Leptoseris, family Agariciidae, based on corallum macromorphology. Since then, it has remained poorly studied and has been known only from a small number of specimens from relatively deep reef environments in the Red Sea and the Chagos archipelago, northern Indian Ocean. Access to museum collections enabled examination of type material and the recovery of coral skeletons from the Seychelles, Madagascar, and Mayotte, southern Indian Ocean. A recent survey in Mayotte allowed the in situ imaging of Craterastrea in shallow and turbid reef environments and sampling for molecular analyses. The molecular analyses were in agreement with the examination of micromorphology and microstructure of skeletons by revealing that Craterastrea levis, the only species in the genus, differs much from Leptoseris foliosa, with which it was synonymized. Moreover, Craterastrea is closely related to Coscinaraea, Horastrea and Anomastraea. However, these genera, currently ascribed to the Siderastreidae, are genetically distant to Siderastrea, the family's type genus, and Pseudosiderastrea. Hence, we restore the genus Craterastrea, describe the new family Coscinaraeidae due to its deep evolutionary divergence from the Siderastreidae, and provide revised diagnoses of the four genera in the family. The description of the new family Coscinaraeidae is a further step in the challenging but ongoing process of revision of the taxonomy of scleractinian corals as a result of the molecular systematics revolution.
Staghorn corals (genus Acropora) are the most obvious and important corals on coral reefs throughout the world, providing much of the beauty and variety seen on the reefs. This invaluable reference tool is the first major review of Acropora in over 100 years. It assesses all the known species worldwide, describing each in detail and illustrating the range of variability of form with habitat and geographic location. The classification, evolution and worldwide distribution of all species are reviewed and illustrated with colour plates, full page black and white plates and distribution maps. Details of the general biology of staghorn corals are discussed and illustrated.
This revision is the result of a study of the genotype species, mostly of type or topotype specimens, of nearly every described scleractinian genus. The classification proposed rests primarily on the structure of the septa, but other skeletal structures as well as the soft parts are utilized and considered. The order Scleractinia is divided into five suborders: Astrocoeniida, Fungiida, Faviida, Caryophylliida, and Dendrophylliida. The first is quite distinct from the others and includes corals with septa composed of relatively few trabeculae. The other four include corals in which the septa consist of a relatively large number of trabeculae. The Fungiida is marked by the fundamentally fenestrate arrangement of the trabeculae, whereas the arrangement is laminar in the Faviida, Caryophylliida, and Dendrophylliida. In the Faviida the septal margins are dentate; in the Caryophylliida they are smooth; and in the Dendrophylliida some septa may become secondarily lacerate or dentate. The subdivision of the suborders into lesser categories is based upon the modification of septal structure and other skeletal elements, mode of colony - formation, form of the corallum, and phylogeny of the groups.
The systematic classification is prefaced by an historical résumé of previous investigations of the Scleractinia and a brief discussion of the anatomy and morphology of the polyps and skeletal structures. The several different modes of sexual and asexual reproduction and increase are carefully analyzed because of their relation to growth form and from this is developed a discussion of morphogenesis of the corallum. Considerable attention is paid to the ecology of recent corals—much is known concerning the reef-building forms, but certain aspects of the ecology of the ahermatypic or non-reef-builders are here extensively considered for the first time. The distribution of fossil and recent scleractinian faunas is broadly analyzed and some suggestions concerning the evolution of the order are made.
A classified list of over a thousand titles dealing with all aspects of the Scleractinia and fifty-one plates illustrating nearly three-fourths of the approximately 500 genera recognized conclude the work.
A multiple sequence alignment program, MAFFT, has been developed. The CPU time is drastically reduced as compared with existing
methods. MAFFT includes two novel techniques. (i) Homo logous regions are rapidly identified by the fast Fourier transform
(FFT), in which an amino acid sequence is converted to a sequence composed of volume and polarity values of each amino acid
residue. (ii) We propose a simplified scoring system that performs well for reducing CPU time and increasing the accuracy
of alignments even for sequences having large insertions or extensions as well as distantly related sequences of similar length.
Two different heuristics, the progressive method (FFT‐NS‐2) and the iterative refinement method (FFT‐NS‐i), are implemented
in MAFFT. The performances of FFT‐NS‐2 and FFT‐NS‐i were compared with other methods by computer simulations and benchmark
tests; the CPU time of FFT‐NS‐2 is drastically reduced as compared with CLUSTALW with comparable accuracy. FFT‐NS‐i is over
100 times faster than T‐COFFEE, when the number of input sequences exceeds 60, without sacrificing the accuracy.
A total of 237 species of azooxanthellate Scleractinia are reported for the Australian region, including seamounts off the eastern coast. Two new genera (Lissotrochus and Stolarskicyathus) and 15 new species are described: Crispatotrochus gregarius, Paracyathus darwinensis, Stephanocyathus imperialis, Trochocyathus wellsi, Conocyathus formosus, Dunocyathus wallaceae, Foveolocyathus parkeri, Idiotrochus alatus, Lissotrochus curvatus, Sphenotrochus cuneolus, Placotrochides cylindrica, P. minuta, Stolarskicyathus pocilliformis, Balanophyllia spongiosa, and Notophyllia hecki. Also, one new combination is proposed: Petrophyllia rediviva. Each species account includes an annotated synonymy for all Australian records as well as reference to extralimital accounts of significance, the type locality, and deposition of the type. Tabular keys are provided for the Australian species of Culicia and all species of Conocyathus and Placotrochides. A discussion of previous studies of Australian azooxanthellate corals is given in narrative and tabular form. This study was based on approximately 5500 previously unreported specimens collected from 500 localities, as well as a re-examination of most of the types and previously reported specimens from the Australian region. Fifty-six species are recorded as new to Australia; 183 state range extensions are listed; and 96 worldwide bathymetric range extensions are noted. In order to characterize the Australian fauna, all 703 known azooxanthellate species were tabulated as to coloniality, method of attachment, and depth range: 187 species are colonial, 516 solitary; 373 are attached, 265 free, and 54 transversely dividing; and 2001000 in is the most common depth range. Compared to all azooxanthellate species, those from Australia have a slightly higher percentage of species that are solitary and unattached (or transversely dividing), due to a disproportionate number of species in the families Flabellidae and Turbinoliidae. Bathymetrically they are typical of the worldwide fauna. Sixty-seven species are endemic to the Australian region. Both UPGMA cluster analysis and MDS ordination reveal two main regions: a northern tropical region and a southern warm temperate region, consistent with zonation patterns of shallow-water marine invertebrates.
— We studied sequence variation in 16S rDNA in 204 individuals from 37 populations of the land snail Candidula unifasciata (Poiret 1801) across the core species range in France, Switzerland, and Germany. Phylogeographic, nested clade, and coalescence analyses were used to elucidate the species evolutionary history. The study revealed the presence of two major evolutionary lineages that evolved in separate refuges in southeast France as result of previous fragmentation during the Pleistocene. Applying a recent extension of the nested clade analysis (Templeton 2001), we inferred that range expansions along river valleys in independent corridors to the north led eventually to a secondary contact zone of the major clades around the Geneva Basin. There is evidence supporting the idea that the formation of the secondary contact zone and the colonization of Germany might be postglacial events. The phylogeographic history inferred for C. unifasciata differs from general biogeographic patterns of postglacial colonization previously identified for other taxa, and it might represent a common model for species with restricted dispersal.
Kitahara, M.V., Cairns, S.D., Stolarski, J. & Miller, D.J. (2012). Deltocyathiidae, an early-diverging family of Robust corals (Anthozoa, Scleractinia). —Zoologica Scripta, 00, 000–000.
Over the last decade, molecular phylogenetics has called into question some fundamental aspects of coral systematics. Within the Scleractinia, most families composed exclusively by zooxanthellate species are polyphyletic on the basis of molecular data, and the second most speciose coral family, the Caryophylliidae (most members of which are azooxanthellate), is an unnatural grouping. As part of the process of resolving taxonomic affinities of ‘caryophylliids’, here a new ‘Robust’ scleractinian family (Deltocyathiidae fam. n.) is proposed on the basis of combined molecular (CO1 and 28S rDNA) and morphological data, accommodating the early-diverging clade of traditional caryophylliids (represented today by the genus Deltocyathus). Whereas this family captures the full morphological diversity of the genus Deltocyathus, one species, Deltocyathus magnificus, is an outlier in terms of molecular data, and groups with the ‘Complex” coral family Turbinoliidae. Ultrastructural data, however, place D. magnificus within Deltocyathiidae fam. nov. Unfortunately, limited ultrastructural data are as yet available for turbinoliids, but D. magnificus may represent the first documented case of morphological convergence at the microstructural level among scleractinian corals. Marcelo V. Kitahara, Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, S.P. 11600-000, Brazil. E-mail:kitahara@usp.br
A reef formed by corals of the azooxanthellate scleractinian genus Eguchipsammia Cairns, 1994 (Dendrophylliidae), identified following the morphological descriptions by Zibrowius (1980) and Cairns (2000), was discovered in July 2013 off the Faial-Pico Channel (Azores, Northeast Atlantic). This is the first record of such an extensive living Eguchipsammia framework and the first major discovery by the Rebikoff-Niggeler Foundation with its recently-inaugurated manned submersible Lula 1000.
Molecular studies have been instrumental for refining species boundaries in the coral genus Pocillopora and revealing hidden species diversity within the extensively studied global species Pocillopora damicornis. Here we formally revise the taxonomic status of species closely related to and within the P. damicornis species complex, taking into account both genetic evidence and new data on morphometrics, including fine-scale corallite and coenosteum structure. We found that mitochondrial molecular phylogenies are congruent with groups based on gross-morphology, therefore reflecting species-level differentiation. However, high levels of gross morphological plasticity and shared morphological characteristics mask clear separation for some groups. Fine-scale morphological variation, particularly the shape and type of columella, was useful for differentiating between clades and provides an excellent signature of the evolutionary relationships among genetic lineages. As introgressive hybridization and incomplete lineage sorting complicate the delineation of species within the genus on the basis of a single species concept, the Unified Species Concept may represent a suitable approach in revising Pocillopora taxonomy. Eight species are herein described (P. damicornis, P. acuta, P. aliciae, P. verrucosa, P. meandrina, P. eydouxi, P. cf. brevicornis), including a novel taxon – Pocillopora bairdi sp. nov. (Schmidt-Roach, this study). Citation synonyms and type materials are presented.
Data on genetic structure of corals living in the Mediterranean Sea are very scarce. Leptopsammia pruvoti Lacaze-Duthiers, 1897, is a gonochoric and brooding solitary coral that colonizes shaded rocky habitats. It is very abundant under overhangs, in caverns, and in small crevices, with typical densities of thousands of polyps per square meter. In the present study, a hierarchical survey of spatial models of genetic structure and potential gene flow was conducted within and among seven shallow water Mediterranean populations, which ranged from 2 to 872 km apart. Within each population, polyps were randomly collected from three patches 5 m apart. Seven allozyme loci indicated a genetic structure characterized by (1) a marked departure from Hardy-Weinberg equilibrium, with a considerable deficit of heterozygotes; (2) most genetic differentiation occurring between patches within populations (F ST = 0.118 to 0.206), rather than among distant populations (F ST = 0.052); and (3) no significant correlation between genetic differentiation and geographic distance. Localized recruitment with consequent biparental inbreeding or Wahlund effect, associated with a proportion of larvae that undergo long-distance dispersal, could explain the observed pattern of genetic structure.
Abstract Budd, A.F. and Stolarski, J. 2009. Searching for new morphological characters in scleractinian reef corals: comparison of septal teeth and granules between Atlantic and Pacific Mussidae. —Acta Zoologica (Stockholm) 90: 142–165. Recent molecular analyses have challenged the traditional classification of scleractinian corals at all taxonomic levels suggesting that new morphological characters are needed. Here we tackle this problem for the family Mussidae, which is polyphyletic. Most of its members belong to two molecular clades composed of: (1) Atlantic Mussidae and Faviidae (except Montastraea) and (2) Pacific Mussidae (Cynarina, Lobophyllia, Scolymia, Symphyllia) and Pectiniidae. Other Pacific mussids (e.g. Acanthastrea) belong to additional clades. To discover new characters that would better serve as phylogenetic markers, we compare the skeletal morphology of mussid genera in different molecular-based clades. Three sets of characters are considered: (1) macromorphology (budding; colony form; size and shape of corallites; numbers of septal cycles), (2) micromorphology (shapes and distributions of septal teeth and granules), and (3) microstructure (arrangement of calcification centres and thickening deposits within costosepta). Although most traditional macromorphological characters exhibit homoplasy, several new micromorphological characters are effective at distinguishing clades, including the shapes and distribution of septal teeth and granules, the area between teeth, and the development of thickening deposits. Arrangements of calcification centres and fibres differ among clades, but the fine-scale structure of thickening deposits does not.
The reef-building coral genus Acropora worldwide is reviewed and revised on the basis of skeletal morphology and field characteristics, using new data from a specimens database of 15,500 specimens from around 800 sites. All type collections in museums throughout the world are reviewed, and lectotypes are designated from syntype series in order to stabilise nomenclature. The question of the identity of the type species of the genus, Acropora muricata (Linnaeus, 1758) is addressed, and a neotype for this species is designated. The fossil species and their distributions through time and space are briefly reviewed. Issues of species boundaries, reticulate phylogenies, hybridisation and genetic delimitation of species are discussed from the literature and some predictions about future changes to taxonomic treatment of the genus are made. The literature on life histories, anatomy, biology and ecology is reviewed. Using the specimens database and the literature, distribution ranges of species are delimited and biogeographic patterns are recognised. Phylogenetic analyses, based on skeletal acters, are presented, and the implications for groupings of species and relationships of species groups are presented. The resulting revised classification of Acropora is used for the systematic discussion of species. Transformation of character states is followed through the proposed phylogeny, leading to a hypothesis of the pattern of evolution of characters and character combinations in Acropora. The genus is distinguished by the characters of corallite dimorphism and centrifugal budding and is proposed to be most closely related to Astreopora amongst the extant Acroporidae. The division into two subgenera A. (Acropora) and A. (Isopora) is maintained. The subgenus A. (Acropora) is seen to have evolved through simple, sturdy species whose axial corallites provide the bulk of the branch and whose coenosteum is uniform and dense, to more complex, slender-branched species with a greater relative number of axial corallites but less bulk. During this process, the radial corallites became less like the axial corallites and a number of lineages with unique radial corallite shapes developed. Coenosteal structure of the axial and radial corallites is seen to have become uncoupled during this process, leading to some lines in which this character is highly differentiated between axial and radial corallites, but the two become equivalent again in the most derived clades. The character of determinate versus indeterminate colony growth mode does not influence the phylogeny. When the cladograms of species relationships are examined in terms of the biogeographic ranges of species, coupled with the fossil records of Acropora, an hypothesis of origination within the African-European region during or before the Paleocene is favoured. This event is seen to be followed by an expansion to the east and west. Closure of the Mediterranean at my probably began the process of isolation of the Atlantic fauna. The genus is seen to have diversified in the central Indo-Pacific during the Neogene. Peripheral species, found in the western Indian Ocean and the central Pacific, and the rarity of several species in the Indo-Australian Arc, are taken to indicate some isolation and expansion of the central Indo-Pacific marine region during late Neogene to Holocene times. The youngest clades in the subgenus A. (Acropora) are dominated by species with ranges in the Indo-Australian Arc or western Pacific. Thus overall, the hypothesis of a gradual transfer of the centre of greatest diversity of the genus from the African-European region to the central Indo-Pacific, with various vicariant events mediating, is favoured.
A solitary octocoral (Taiaroa tauhou gen. et sp. nov., family Taiaroidae, new fam.) discovered off the east coast of the South Island of New Zealand is described. Anatomy and histology were studied from sections prepared by the traditional paraffin technique and from specimens embedded in epoxy resin. Sclerites are illustrated by scanning electron micrographs.
Heteropsammia michelinii, a free-living and free-moving scleractinian coral found in the Australian Great Barrier Reef, has a symbiotic association with a sipunculid worm, Aspidosiphon corallicola. The worm lives in a cavity on the under surface of the coral and it pulls the coral over the muddy surface of the sand.