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New records of marine invertebrates from the coast of Gabon, Eastern Atlantic
Abstract
An underwater inventory mission was conducted in November 2017 by six
naturalists on the north rocky coast of Gabon between Cape Esterias and
Cape Santa Clara.
The following twenty-six species are recorded from the coast of Gabon for
the first time : the protozoan Zoothamnium niveum, the octocoral Carijoa
riisei, the sea anemone Actinostella flosculifera, the plathelmint Pseudobiceros
wirtzi, nine opisthobranch molluscs, the polychaete Eurythoe sp., the
mudshrimp Neaxius mclaughlinae, seven species of true shrimps, a possibly
undescribed pagurid hermit crab, the mantis shrimp Protosquilla sp., the cirriped
Conopea saotomensis, and the sea cucumber Isostichopus cf badionotus.
For some of these species, this is a large extension of the known range of
distribution. The poorly explored coasts of Gabon apparently harbour many
still undetected species.
... These swarmers produced (6); Red sea (7); Tokyo bay (8); White Point Beach in California, USA available genome for Thiobius zoothamnicola, this paper (9); Indian River Lagoon as well as Pete stone's creek located in Florida, USA (10); Madeira Island (11); São Tomé Island (12); Gabon (13); Giglio Island, Italy (14); and Cyprus Island (15). Supplementary Table S1 provides more details on the Z. niveum locations, including literature citations: (Indian River Lagoon Species Inventory, n.d.; Frenkiel et al., 1996;Wirtz and Debelius, 2003;Nyholm and McFall-Ngai, 2004;Goffredi et al., 2005;Wirtz, 2008;Laurent et al., 2009;Kawato et al., 2010;Petersen et al., 2011;Laurent et al., 2013;Lorion et al., 2013;Riehl and Frederickson, 2016;Wirtz, 2018;Wirtz and Serval-Roquefort, 2020;Sogin et al., 2020;Roger et al., 2021;Fokin and Serra, 2022;Lin et al., 2023). ...
Symbiotic interactions drive species evolution, with nutritional symbioses playing vital roles across ecosystems. Chemosynthetic symbioses are globally distributed and ecologically significant, yet the lack of model systems has hindered research progress. The giant ciliate Zoothamnium niveum and its sulfur-oxidizing symbionts represent the only known chemosynthetic symbiosis with a short life span that has been transiently cultivated in the laboratory. While it is experimentally tractable and presents a promising model system, it currently lacks an open-source, simple, and standardized cultivation setup. Following the FABricated Ecosystems (EcoFABs) model, we leveraged 3D printing and polydimethylsiloxane (PDMS) casting to develop simple flow-through cultivation chambers that can be produced and adopted by any laboratory. The streamlined manufacturing process reduces production time by 86% and cuts cost by tenfold compared to the previous system. Benchmarking using previously established optimal growth conditions, the new open-source cultivation system proves stable, efficient, more autonomous, and promotes a more prolific growth of the symbiosis. For the first time, starting from single cells, we successfully cultivated the symbiosis in flow-through chambers for 20 days, spanning multiple generations of colonies that remained symbiotic. They were transferred from chamber to chamber enabling long-term cultivation and eliminating the need for continuous field sampling. The chambers, optimized for live imaging, allowed detailed observation of the synchronized growth between the host and symbiont. Highlighting the benefit of this new system, we here describe a new step in the first hours of development where the host pauses growth, expels a coat, before resuming growth, hinting at a putative symbiont selection mechanism early in the colony life cycle. With this simple, open-source, cultivation setup, Z. niveum holds promises for comparative studies, standardization of research and wide adoption by the symbiosis research community.
... Only two species of Conopea were known from the Atlantic Ocean when Carrison-Stone et al. (2013) described Conopea saotomensis and Conopea fidelis from gorgonians (Leptogorgia and Eunicella) at São Tomé and Príncipe. Subsequently, Wirtz et al. (2020) reported C. saotomensis from Eunicella sp. at the coast of Gabon (based on examination of specimens by R. Van Syoc). Here we report the first record of C. saotomensis from three islands in the Bijagós archipelago, Guinea-Bissau, extending the known range of the species about 3000 km to the northwest (measured as a straight line from northern Gabon to the Bijagós archipelago) (Figure 2). ...
Barnacles of the genus Conopea are obligate epibionts of gorgonians and antipatharians. The species Conopea saotomensis Carrison-Stone et al. 2013, previously only known from the islands of São Tomé and Príncipe and the coast of Gabon, is reported from the Bijagós archipelago, Guinea-Bissau, based on morphological examination and DNA barcoding of specimens. The new record extends the known range of the species about 3000 km to the northwest.
... Telesto africana Verrill, 1870 should be included within Carijoa genus; surely an endemic African species, to be redescribed in the future, that cannot be C. riisei because its large sclerites of 0.5 mm. Records from Gabon (Wirtz, 2020) does not appear to belong to Carijoa; one specimen presents similar colour pattern to that observed in Cryptocarijoa (see present article); the second one shows a different colour pattern. In Hawaii, one of the Carijoidae species has been recorded in mesophotic habitats without morphological studies (Kahng & Grigg, 2005). ...
Researchers have been using the name Carijoa riisei and its invasive behaviour without accurate evidence of either. Nevertheless, cryptodiversity is a very difficult subject, and thanks to these articles and their scientific information, a real interest about Carijoidae merged. Although the populations of Carijoidae distributed in Tenerife and Gran Canaria share a similar appearance, the discovery of six new species and three new genera demonstrates the necessity for further research to elucidate the cryptodiversity concealed within the Carijoidae family (see McFadden, van Ofwegen & Quattrini, 2022). According to our observations, these species have not shown invasive behaviour in Canary Islands. This is, also confirmed by genetic research (see Rosales et al., 2024, in revision). However, they do constitute a potential threat to the Canarian marine ecosystem. Therefore, an urgent monitoring program to search for the expansion of these populations and any other yet to be studied populations, should be performed by the marine protected authorities
... In Hawaii, it has spread to 90% of the area occupied by black coral (Antipathes spp.), collapsing black coral fisheries, and causing substantial economic damage (Kahng and Grigg 2005). It has been reported in multiple locations in the last ten years, including India, Mexico, Gabon, and Ecuador (Venkataraman et al. 2016, Galván-Villa and Ríos-Jara 2018, Steiner et al. 2018, Wirtz et al. 2020, Cárdenas-Calle et al. 2021. Thus, C. riisei has been included in the International Union for Conservation of Nature (IUCN) Global Invasive Species Database (2022). ...
Octocorals are the main component of rocky walls in the Panamanian tropical eastern Pacific (TEP), providing shelter and substrate for diverse marine invertebrates and demersal fishes. Despite their ecological importance, many essential biological traits of these corals remain undescribed. Like some cnidarians, octocorals may be related to bioinvasion. One emerging risk is the rise of the Indo-Pacific invasive octocoral Carijoa riisei , which overgrows other soft corals, competing for food and space and promoting the emergence of diseases. Considering the potential risk to native octocorals, we investigated the reproductive seasonality of C. riisei at 15 m depth every month for one year in the Gulf of Panama (Las Perlas Archipelago), an octocoral diversity hotspot with seasonal upwelling. Carijoa riisei showed an average fecundity (percentage of polyps with eggs sampled throughout the year from only female colonies) of 53% (SE 0.03%) with no seasonality. Carijoa riisei produced eggs continuously with overlapping generations, with an average of 23 (1–107; SE 0.75) eggs per fertile polyp and an average egg diameter of 0.12 (0.10–0.64; SE 0.0008) mm. The number of eggs inside the gastrovascular cavity was higher during the upwelling. However, the size and proportion of large eggs were greater towards the end of the upwelling season, with a drastic decrease from 30% to 2% at its end. Our results over a one-year sampling period show that in the Panamanian TEP, C. riisei reproduces continuously, seemingly energized by higher nutrient levels present during upwelling. This, along with its rapid growth rate, makes this species a formidable competitor for native species. Thus, we encourage future monitoring of these populations.
... This species is widely distributed in the western Atlantic, with reports from Bermuda to southern Brazil, including the south-eastern Gulf of Mexico (Verrill, 1869;Garese et al., 2009;González-Muñoz et al., 2012, 2016Durán-Fuentes et al., 2022; Smithsonian's National Museum of Natural History, accessed online 25 February 2022), but it also occurs in the Canary Islands (Ocaña & den Hartog, 2002) and the Gulf of Guinea (Wirtz, 2003, Wirtz et al., 2020. However, little is known about the ecology of A. flosculifera, especially in the South-western Atlantic. ...
Sea anemones have developed various strategies for interspecific interaction with other organisms and their own ability to obtain food, due to their coevolutionary history, ranging from mutualistic (e.g. clownfish, crustaceans, etc.) and symbiotic associations (zooxanthellae or zoochlorellae) to depredation (e.g. sea slug). This study aims to record some observations on feeding habits and interspecific interactions of Actinostella flosculifera (Le Sueur, 1817) in the locality of Pedra da Sereia in Vila Velha, Espírito Santo, Brazil, and to describe the hunting strategy of the sea slug Spurilla braziliana MacFarland, 1909 and the escape strategy of A. flosculifera. We found that the habitat of A. flosculifera is characterized by shallow pools ∼10 cm deep at low tides, and this functions as a trap for many organisms and some biowaste (e.g. bones or fish drifting in from nearby populations) that fall into the oral disc. This is the first report of S. braziliana predating on A. flosculifera. We also report interspecific relationships between A. flosculifera with four species of crustaceans: Omalacantha bicornuta (Latreille, 1825), Menippe cf. nodifrons Stimpson, 1859, Alpheus cf. angulosus McClure, 2002, and Alpheus cf. carlae Anker, 2012.
... Finally, a recent contribution regarding the biodiversity of the coasts of Gabon (Wirtz et al. 2020) showed a picture of a flatworm species under the name Pseudobiceros wirtzi. We suggest that actually this specimen belongs to P. principensis. ...
A new species of polyclad flatworm belonging to the genus Pseudobiceros Faubel, 1984 is described based on external and internal morphological features from specimens collected on the coasts of Principe Island. Pseudobiceros principensis sp. nov. is a large-sized worm, with well-developed pseudotentacles, an elongated oval body shape, and deep marginal ruffles. It is characterized by a blackish to reddish background color, with scattered yellow and white spots or stripes of different sizes (forming a star-like shape) along the whole dorsal surface.
This study aimed to explore and document putative exotic marine benthic invertebrate species in the Bijagós Archipelago, Guinea‐Bissau, to enhance understanding of marine biodiversity and address the extent of marine species introductions. The research was conducted in the Bijagós Archipelago, a UNESCO Biosphere Reserve located in Guinea‐Bissau. The study involved the region's first scuba‐diving survey of marine biodiversity. DNA barcoding was employed to assist in the identification of benthic invertebrate species. Molecular phylogenetic analyses were conducted with the available DNA barcodes to ensure accurate taxonomic assignments, detect cryptic species, and investigate the phylogeography of the taxa. The survey resulted in the discovery of 28 new species records for the Bijagós Archipelago, including octocorals, scleractinians, hydroids, bryozoans, barnacles, and ascidians. Among these, six species were documented for the first time in the East Atlantic: Stragulum bicolor, Nemalecium lighti, Diphasia sp., Amathia alternata, A. distans, and Symplegma rubra. Molecular analyses revealed pervasive cryptic diversity within species previously listed as exotic, suggesting that some, such as the hydroids Plumularia setacea, Obelia geniculata, and Dynamena disticha, are not exotic due to their restricted biogeographic distributions. Many other species reported as introduced present only a few genetic lineages capable of long‐distance dispersal due to human activities. The study highlights considerable gaps in the knowledge of West African marine biodiversity and suggests a substantial underestimation of the anthropogenic trade in exotic marine species between the Tropical East Atlantic and the Americas, and between the Indo‐Pacific, Mediterranean, and West Africa. Detailed taxonomic and genomic analyses are necessary for understanding marine exotic species' biogeography and adaptive traits. Our findings challenge current classifications of exotic species and underscore the need for improved monitoring and management to prevent the spread of non‐native marine species.
Isostichopus badionotus (Selenka, 1867) is distributed in the Atlantic Ocean. It has been recognized as a species with highly variable intraspecific coloration. To clarify taxonomic confusion and show the characters for correct identification of this valuable species, mitochondrial DNA (16S and COI), color patterns, external and internal morphology, ossicles, and habitat were examined in specimens from museum collections and from original sampling. As part of the revision, I. fuscus (Ludwig, 1875) from the Eastern Pacific Ocean and I. macroparentheses (Clark, 1922) from the Caribbean Sea, the only other two species currently recognized in the genus Isostichopus, were included. It was concluded that I. fuscus and I. macroparentheses are distinct and valid species, and that I. badionotus consists of two species: I. badionotus and I. maculatus (Greeff, 1882), previously synonymized as I. baqdionotus by Clark (1922). Isostichopus maculatus includes two subspecies, the nominal I. maculatus maculatus (Greeff, 1882) and I. maculatus phoenius (Clark, 1922), described as Stichopus badionotus var. phoenius Clark, 1922. Isostichopus maculatus maculatus, distributed in the East Atlantic, is very similar to I. maculatus phoenius, but differs in DNA characters, color pattern, and the size and shape of the tables in the dorsal papillae. Isostichopus maculatus phoenius, widely distributed in the Caribbean Sea and the Gulf of Mexico, is sympatric with I. badionotus, has similar ossicles but is clearly distinguished by its DNA sequences, color patterns, and habitat preferences. For the first time, ossicles from internal organs are described for Isostichopus, enhancing original species descriptions. Distribution maps, habitat, biology, conservation status, and a taxonomic key for distinguishing these species to aid their fishery management and aquaculture are presented.
Species of the decapod family Palaemonidae are common components of tropical coastal waters and coral reefs. The majority of these species are symbionts of various invertebrate phyla. Despite a long history of research on their species diversity in the Dutch Caribbean, recent field expeditions have yielded much new information. Combined with examinations of specimens housed in Naturalis Biodiversity Center and information from literature, a comprehensive list of Dutch Carribean palaemonids is provided. Newly collected material was primarily identified via morphological analyses. Additional molecular phylogenetic analyses based on mitochondrial COI and 16S and nuclear Histone 3 (H3) genes were conducted in search of cryptic species on the one hand and to check conspecifity in species that were found on multiple host species on the other hand. In total, 46 species are here listed for the Dutch Caribbean of which 24 are here recorded for the first time for one of the islands. One species new to science was discovered and is herein described. Sixty new host associations are recorded. In light of biodiversity loss and increasing anthropogenic pressure on declining coral reefs, documenting the diversity of palaemonids and other coral reef species to provide baseline data takes on a new urgency.
Rocky shore fishes Gabon (in French), with many photos and new records
The following species are recorded from the coasts of São Tomé and Príncipe for the first time: the ciliate Zoothamnium niveum, the black coral Antipathella wollastoni, the zoanthid Isaurus tubercularis, and the shrimp Latreutes fucorum. The presence of the black coral Tanacetipathes spinescens and of the shrimp Cinetorhynchus rigens is confirmed. The presence of the crab Platypodiella picta at São Tome Island is confirmed and a possibly undescribed species of Platypodiella is recorded from Principe Island. Mistaken records of Stichopathes lutkeni are corrected: the species at São Tomé and Príncipe is Stichopathes occidentalis.
A new species of the chromodorid genus Felimare (Gastropoda: Heterobranchia) of the Atlantic blue chromatic group is described using material from Cape Verde (eastern Atlantic). Felimare aurantimaculata n. sp. was described based on morphological characters, as well as a molecular phylogeny using two mitochondrial (cytochrome c oxidase subunit I and 16S rRNA) and one nuclear (histone-3) markers. Felimare aurantimaculata n. sp. is characterized by having a ground of dark blue colour with many orange polka dots over the body, dark blue rhinophores and branchial leaves, and very large and not clustered mantle dermal formations (MDFs) at the edge of the mantle, totally absent in the anterior area facing the rhinophores.
The occurrence of the rays belonging to the genera Mobula (known collectively as the ‘devil rays’) and Manta is poorly documented in the eastern tropical Atlantic. Between August 2004 and September 2005, a total of 28 mobulid ray observations were recorded from geophysical survey vessels operating in the waters between Gabon and Angola. Water depth at the location of the sightings varied from 30 to 4000 m, reflecting an occurrence in both neritic and oceanic habitat. While most animals were unidentified to species level, photographs taken during two sightings facilitated the identification of two separate species/species groups of Mobula. The first individual, photographed at the surface in deep water offshore of northern Angola, was identified as belonging to the M. mobular/M. japanica species group, comprising two species that are very similar in appearance and which future evidence may reveal to represent a single species. The second animal, photographed off Pointe Noire in the Republic of the Congo, was identified as a bentfin devil ray (M. thurstoni). The previously documented southernmost records of these species in the eastern tropical Atlantic were in the Mediterranean Sea (M. mobular), Côte d'Ivoire (M. japanica) and Senegal (M. thurstoni). These observations therefore extend the known distribution ranges into the south-east Atlantic Ocean.
RESUMEN El nombre Navanax aenigmaticus (Bergh, 1894) aplicado a poblaciones de babosas marinas con un diseño cromático similar en 3 regiones biogeográficas distintas, ha sido re-cientemente dividido, en tres nombres, uno por región: Navanax gemmatus (Mörch 1863) (Región Caribeña), N. aenigmaticus (Bergh, 1894) (Región Panámica) y Navanax nyanya-nus (Edmunds 1968) (Región Atlántica Tropical Oriental). Se propone la revalidación del nombre Navanax orbignyanus (Rochebrune, 1881) para la especie africana al tener prioridad sobre P. nyanyanus y ser perfectamente reconocible con los datos aportados en la descripción original. Se designa un neotipo para darle estabilidad. ABSTRACT The name Navanax aenigmaticus (Bergh, 1894) has been applied to populations of marine slugs with a common color design inhabiting 3 biogeographic regions. Recently it has been elucidated that for each region a different name should be applied: Navanax gemmatus (Mörch 1863) (Caribbean Region), N. aenigmaticus (Panamic Region) and Navanax nyanyanus (Edmunds 1968) (Tropical East Atlantic Region). We propose the reinstatement of the name Navanax orbignyanus (Rochebrune, 1881) for the african species due to its priority over P. nyanyanus. N. orbignyanus is easily recognizable with the data provided in the original description. A neotype is designated to give stability to the name.
Molecular and morphological data from newly collected specimens and a review of the literature and type material indicate that the widespread tropical sea hare Dolabrifera dolabrifera is a species complex of five genetically distinct taxa. The name Dolabrifera dolabrifera is retained for a widespread species in the Indo-Pacific tropics. Dolabrifera nicaraguana is endemic to the eastern Pacific. Dolabrifera ascifera, D. virens and a new species described herein are restricted to the tropical Atlantic, with partially overlapping ranges in the Caribbean region and St. Helena. The temperate Pacific species Dolabrifera brazieri is also distinct and endemic to temperate southeastern Australia and New Zealand. These species of Dolabrifera constitute highly divergent lineages and most contain unique internal anatomical characteristics, particularly in the male reproductive morphology and shell shape, making them relatively easy to identify upon dissection. However, externally all these species are extremely variable in colour pattern and morphology and are virtually indistinguishable. This is particularly problematic for identification in the Atlantic Ocean where three species co-occur in the Caribbean region.
The habitat preferences and niches of eight cetacean species inhabiting eastern tropical Atlantic waters between Angola and Gabon (1°N–11°S latitude) were examined. A total of 2873 cetacean sightings, recorded between January 2004 and June 2009, was assigned to 10 × 10 km grid cells and linked to four ecogeographical variables (EGVs): water depth, seabed slope, sea surface temperature (SST) and relative frontal strength. Classification trees revealed that the habitat preferences (in terms of the habitats sampled) of most species were primarily determined by SST (for Bryde's whale, sperm whale, short-finned pilot whale and common dolphin) and water depth (for Risso's dolphin, bottlenose dolphin and Atlantic spotted dolphin). Seabed slope was the most important EGV describing the presence of the striped dolphin. A principal component analysis was used to compare the niches of the species with respect to the four EGVs. Nineteen species pairs (68%) differed significantly in median principal component (PC) score for the first PC axis, suggesting differences in their niche centres for that axis. Sixteen species pairs (57%) differed significantly in PC score variance suggesting differences in the niche widths along the first PC axis. Water depth and SST were the most important variables for the first PC axis. Together, these results suggest that cetacean species inhabiting the eastern tropical Atlantic exhibit interspecific variation in their habitat preferences, and so differ in the niches that they occupy. These differences are most likely related to variation in prey species and foraging strategy.