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A new classification of viviparous brotulas (Bythitidae) – with the establishment of a new family Dinematichthyidae – based on molecular, morphological and fossil data
... sea, benthopelagic fishes: Sciadonus pedicellaris Garman, 1899; Sciadonus cryptophthalmus (Zugmayer, 1911); Sciadonus jonassoni (Nybelin, 1957); Sciadonus longiventralis Nielsen, 2018; Sciadonus robinsini Nielsen, 2018; and Sciadonus alphacrucis Melo et al., 2022(Fricke et al., 2024Nielsen, 2018;Melo et al., 2022). Previously classified within the Aphyonidae, it was recovered as a monophyletic unit by a phylogenetic study by Møller et al. (2016) utilizing molecular evidence, but nested in Bythitidae; therefore, it is now referred to as the Aphyonid clade (Nielsen et al., 1999). Members of the Aphionid clade are very distinctive from other bythitids by having troglomorphic traits, such as transparent skin, lacking pigmentation, delicate and scale-less skin, skeleton poorly calcified, eyes reduced, the lateral-line canals absent, and only superficial neuromasts present on the head and body (Nielsen, 1969(Nielsen, , 2015(Nielsen, , 2016(Nielsen, , 2018. ...
... Consensus sequences were generated using Geneious software version 4.8.5 (Kearse et al., 2012) and verified by the Basic Local Alignment Search-BLASTn (Altschul et al., 1990) from a threshold of similarity of 98% with the sequences available on the GenBank database. The multiple alignment was performed in Geneious version 4.8.5 with the generated sequence of S. alphacrucis and the sequences of Aphyonidae clade (Fricke et al., 2024;Møller et al., 2016;Nielsen, 1969Nielsen, , 2019Nielsen et al., 1999) (Nielsen, 1974); and ...
Sciadonus alphacrucis Melo, Gomes, Møller & Nielsen, 2022 is a rare deep‐sea species, previously known from only two specimens collected off São Paulo State, southeastern Brazil, in the western South Atlantic. Herein, we report a new specimen of S. alphacrucis collected on the continental slope off Santa Catarina State, southern Brazil, thereby extending its known distribution by 420 km. Additionally, we provide the new meristic and morphometric data, the molecular identification using sequences of the cytochrome c oxidase subunit I (COI), an updated distribution map, and a discussion of troglomorphic traits.
... Barathronus Goode & Bean, 1886 was previously included in the family Aphyonidae Jordan & Evermann 1898, but Møller et al. (2016) placed Aphyonidae as a derived clade of the family Bythitidae Gill, 1861. This genus is characterized by having joined vertical fins; loose and transparent scaleless skin; mouth almost vertical, with fangs on vomer, dentaries, and occasionally on palatines; 20-35 long gill rakers on the first branchial arch; 62-84 dorsal-fin rays, 46-73 anal-fin rays, 21-27 pectoral-fin rays, and one pelvic-fin ray; 31-38 precaudal vertebrae and 67-89 total vertebrae; adult specimens with hourglass-shaped vertebral centra and mature males with penis length up to 15% L S (Nielsen, 2019). ...
... Although traditional fish species identification has relied heavily on external morphological characters, there is a growing trend to use molecular taxonomy for this purpose . A few molecular markers have been previously used in Barathronus species for taxonomic or phylogenetic purposes: cytochrome c oxidase subunit I (COI) (Chang et al., 2017;Evseenko et al., 2018;Nielsen et al., 2019), 16S ribosomal RNA (16S) and NADH (Nicotinamide Adenine Dinucleotide + Hydrogen) dehydrogenase subunit 4 (ND4) (Evseenko et al., 2018;Møller et al., 2016;Near et al., 2013), and recombination activating protein 1 (RAG1) (Evseenko et al., 2018;Near et al., 2013). ...
Barathronus is a genus of blind cusk eels comprising 11 valid species. In this paper, we report the second specimen ever documented of Barathronus roulei (Bythitidae) obtained from the Porcupine Bank by R.V. Vizconde de Eza using a bottom trawl at a depth of 1349 m. Morphological description and illustrations, including a radiograph, are provided. In addition, three new sequences corresponding to three different genes, cytochrome c oxidase subunit I (COI)‐DNA barcoding, 16S ribosomal RNA (16S), and recombination activating protein 1 (RAG1), have been added to the molecular repositories, representing the first sequences for the species.
... Sin embargo, recientemente se identificó un error nomenclatural al pasar del género Typhlias a Typhliasina, por lo que se retomó el nombre de Typhlias (Scharf, 2017). A partir de aproximaciones filogenéticas, estimación de tiempos de divergencia y mapeo de caracteres morfológicos en el orden Ophidiiformes, Møller et al. (2016) diagnosticaron a la familia Dinematichthydae. Dicho taxón incluyó a Typhlias pearsei (considerada Typhliasina en Møller et al. 2016) como género monotípico cuyos taxa más cercanos son los géneros marinos Ogilbichthys y Ogilbia. ...
... A partir de aproximaciones filogenéticas, estimación de tiempos de divergencia y mapeo de caracteres morfológicos en el orden Ophidiiformes, Møller et al. (2016) diagnosticaron a la familia Dinematichthydae. Dicho taxón incluyó a Typhlias pearsei (considerada Typhliasina en Møller et al. 2016) como género monotípico cuyos taxa más cercanos son los géneros marinos Ogilbichthys y Ogilbia. Dicho estudio utilizó una reducida cobertura taxonómica. ...
Los peces de cuevas representan un excelente modelo para estudiar la evolución del fenotipo, debido a su alta asociación con el ambiente extremo en el que han evolucionado. La adaptación de estos organismos se ha dado como una respuesta a presiones de selección que se refleja en cambios fenotípicos asociados con su particular estrategia de vida en la oscuridad. Dentro del marco conceptual de la sistemática filogenética, estas adaptaciones se reconocen como convergencias o paralelismos evolutivos. Los peces de cuevas de México están representados en seis de los 10 órdenes de Actinopterygii; presentan diferentes niveles de troglomorfismo asociado al tiempo de aislamiento en las cuevas, y aunque la mayoría son de origen dulceacuícola, también los hay de procedencia marina. Bajo este contexto, las filogenias han tenido importantes implicaciones para la taxonomía y evolución de estos peces.
... Due to constraints associated with pressure adaptation, fishes are believed not to inhabit depths below ~8200 m (Yancey et al., 2014). A few major fish families regularly occur in abyssal depths: Bythitidae (Aphyonus group), Ipnopidae, Liparidae, Macrouridae, Ophidiidae, Synaphobranchidae, and Zoarcidae (Møller et al., 2016;Priede, 2017). Among the few fishes that have been seen or caught below the abyssal-hadal boundary are primarily macrourid rattails, ophidiid cusk eels, and liparid snailfishes (Gerringer et al., 2021b;Linley et al., 2016), with rare observations of synaphobranchids, zoarcids, and other groups such as the Ateleopodidae and Stephanoberycidae (Jamieson et al., 2021). ...
... The fishes constituting the Aphyonus group in the sense of Møller et al. (2016; family Apyonidae sensu Nielsen et al., 1999) are neotenic and live at great depth in the bathyal and abyssal zones of the world oceans. Hadal occurrences are not known. ...
... sea, benthopelagic fishes: Sciadonus pedicellaris Garman, 1899; Sciadonus cryptophthalmus (Zugmayer, 1911); Sciadonus jonassoni (Nybelin, 1957); Sciadonus longiventralis Nielsen, 2018; Sciadonus robinsini Nielsen, 2018; and Sciadonus alphacrucis Melo et al., 2022(Fricke et al., 2024Nielsen, 2018;Melo et al., 2022). Previously classified within the Aphyonidae, it was recovered as a monophyletic unit by a phylogenetic study by Møller et al. (2016) utilizing molecular evidence, but nested in Bythitidae; therefore, it is now referred to as the Aphyonid clade (Nielsen et al., 1999). Members of the Aphionid clade are very distinctive from other bythitids by having troglomorphic traits, such as transparent skin, lacking pigmentation, delicate and scale-less skin, skeleton poorly calcified, eyes reduced, the lateral-line canals absent, and only superficial neuromasts present on the head and body (Nielsen, 1969(Nielsen, , 2015(Nielsen, , 2016(Nielsen, , 2018. ...
... Consensus sequences were generated using Geneious software version 4.8.5 (Kearse et al., 2012) and verified by the Basic Local Alignment Search-BLASTn (Altschul et al., 1990) from a threshold of similarity of 98% with the sequences available on the GenBank database. The multiple alignment was performed in Geneious version 4.8.5 with the generated sequence of S. alphacrucis and the sequences of Aphyonidae clade (Fricke et al., 2024;Møller et al., 2016;Nielsen, 1969Nielsen, , 2019Nielsen et al., 1999) (Nielsen, 1974); and ...
A new species of the rare, deep-sea genus Sciadonus Garman, 1899 (Bythitidae) is described based on two specimens obtained by the Brazilian R/V Alpha Crucis on the continental slope off São Paulo State, Southeastern Brazil, western South Atlantic. It differs from its congeners by the combination of the following characters: body pale lacking dark pigmentation except for on female claspers; a pair of dermal tissue flaps anteriorly on lower jaw; pelvic-fin rays present; precaudal vertebrae 39 or 40 and total vertebrae 74 or 75. The key to the species of Sciadonus is updated. A discussion of the presence and differentiation between troglomorphic and miniature characteristics among the species in the aphyonid clade is provided and compared with other bythitids.
... Barnard noticed that his new species B. capensis belonged to a "small group of Brotulids which have the dorsal and anal fins free from the caudal . . . ". Today, Bidenichthys is placed in the family Bythitidae and is characterized by a male copulatory organ with penis and pseudoclaspers more or less fused, differing from the family Dinematichthyidae with free penis, and pseudoclaspers [2]. Barnard [1] defined the genus and species partly on the very long pectoral fin peduncle and mentioned that the nearest species was Dinematichthys consorbrinus [3] from New Zealand, based on the figure in Hector [4]. ...
... midwayensis [25] from the Paleocene. All these species may actually represent a yet undefined fossil clade near the base of the Bythitoidei [2]. This leaves †Bidenichthys struthersi Schwarzhans [15] (see [15] for figures) as the only valid fossil otolith record of the genus, which is closest to the extant B. slartibartfasti. ...
Two specimens from the Koko Seamount (Koko Guyot), in theHawaiian-Emperor seamount chain, Central North Pacific, caught in 2009 and 2010 are here described as a new species, Bidenichthys okamotoi. The taxonomy of the species in the genera Bidenichthys Barnard, 1934, and Fiordichthys Paulin, 1995, has been confusing due to the lost type of B. consorbrinus (Hutton, 1876) and the rarity of some of the species. Following the synonymization of Fiordichthys Paulin, 1995, with Bidenichthys by Møller and Nielsen 2015 and of Bidenichthys beeblebroxi Paulin, 1995, with Bidenichthys consobrinus Hutton, 1876, the genus Bidenichthys now comprises five species: B. capensis, B. consobrinus, B. okamotoi, B. paxtoni and B. slartibartfasti. Bidenichthys okamotoi differs from its congeners in, e.g., the fewer precaudal vertebrae (12 vs. 13), more palatine teeth rows (4–6 vs. 2–3), shorter pelvic fins (12.1–13.4% vs. 14.4–21.0% SL), max size (187 vs. 147 mm SL) and the shape of the sulcus of the otolith. We here
present an updated diagnosis of the genus. A computed tomography (CT) scan of the holotype of B. okamotoi provides for additional anatomical details. The disjunctive occurrence of Bidenichthys okamotoi on the Emperor Seamount chain about 7500 km from the nearest congeneric taxon in New Zealand is discussed. The fossil otolith-based record of the genus Bidenichthys and its systematic implications is briefly discussed.
... According to Nelson et al. (2016), the order Ophidiiformes includes 5 families (Aphyonidae, Bythitidae, Carapidae, Parabrotulidae, and Ophidiidae), 119 genera and about 530 species. Recently, Møller et al. (2016) introduced a new classification for the viviparous clade, merging Bythitinae, Brosmophysini and Aphyonidae into Bythitidae, and elevating Dinematichthyidae (formerly tribe Dinematichthyini) to family status. Recent studies on the diversity of ophidiiforms from Brazil reported the occurrence of 45 species from 33 genera and 3 families from both coastal and deep-sea waters (Franco et al. 2007, Mincarone et al. 2008, Nielsen 2009, 2015. ...
... More recently, a new aphyonid species from off northeastern Brazil was described as Barathronus linsi Nielsen, Mincarone & Di Dario, 2015. Summing up, the current list of ophidiiform fishes recorded in Brazilian waters, following Møller's et al. (2016) classification, includes 34 genera and 46 species: 9 species of Bythitidae (including P. sanguineus), 4 Carapidae, and 33 Ophidiidae. In a recent study, Pinheiro et al. (2018) reported the presence of 405 resident reef fish species in the western South Atlantic, of which 186 species (46%) are widely distributed in the western Atlantic. ...
The present study reports on the first records of the bythitid Redfin Brotula, Petrotyx sanguineus (Meek & Hildebrand, 1928), in the western South Atlantic, based on 7 specimens (50.8-152.8 mm SL) from 5 localities along the northeastern coast of Brazil: (1) Praia de Maracaípe, Ipojuca and (2) Praia de Tamandaré, Tamandaré, in Pernambuco state; and (3) Praia do Forte, Mata de São João, (4) Praia de Busca Vida, Camaçari, and (5) Barra do Pote, Vera Cruz, in Bahia state. This species was previously known only in the western Central Atlantic, from Bahamas to Trinidad and Tobago, including the Caribbean Sea. In addition to the new distributional information, morphological data are provided based on the specimens examined.
... This molecular work is challenging many of the traditional arrangements in the higher classification of fishes, most notably in Percomorphi and Perciformes (Wiley and Johnson 2010;Betancur et al. 2013;Chen et al. 2014;Miya and Nishida 2014). We consider that these phylogenies are still too much in a state of flux to be applied to our study and therefore, have selected to follow the more 'traditional' classifications of Nelson (2006), Roberts et al. (2015) and the composition of Ophidiiformes following Møller et al. (2016). ...
... Aotearichthys vestalis represents a fossil genus of the Dinematichthyidae (for definition of the family see Møller et al. 2016). There is only one extant dinematichthyid known from New Zealand, Dermatopsis joergennielseni Møller and Schwarzhans 2006, which probably was a fairly recent immigrant and is known from the fossil record since the Pleistocene (Grenfell andSchwarzhans 1999, Møller andSchwarzhans 2006). ...
Fish otoliths are essential tools for reconstructing fossil teleost faunas. Here, we describe otoliths from estuarine to deep-water Late Oligocene localities in southern Zealandia. Thirty-one species are recognised including 14 new species and two new genera. New species are: Moringua waimumuensis n.sp., Heteroconger? mataura n.sp., Tonganago coplandi n.sp., Sardinops robinsoni n.sp., Lotella latidorsalis n.sp., Trachyrincus tewaewae n.sp., Eurypleuron debilis n.sp., Neobythites lindqvisti n.sp., Aotearichthys vestalis n.sp., Centroberyx worthyi n.sp., Krebsiella chattonensis n.sp., Lesueurina transoceana n.sp. and Micropercops pomahaka n.sp., a representative of a basal gobioid family (Odontobutidae) now restricted to fresh- and brackish waters of eastern Asia. The new otolith-based genera are: Aotearichthys n.gen. (Dinematichthyidae) and Tonganago n.gen. (Congridae). The diverse faunal association reflects the range of paleoenvironments from estuarine to deep marine allowing an unusually complete reconstruction of the fish ecosystems. We compare the fauna with the extant marine fauna of Zealandia and discuss its phylogenetic and biogeographic significance.
... Other morphological characteristics such as caudal structure, paired nostrils and a bilobed ovary (Anderson, 1994) as well as the phylogenetic analysis presented here indicate that parabrotulids are ophidiiforms. The phylogenetic analyses place Parabrotulidae within the suborder Bythitoidei, which is known to be viviparous as is Parabrotula tanseimaru (Miya and Nielsen, 1991;Møller et al., 2016). The other suborder of Ophidiiformes, Ophidioidei is oviparous. ...
... The other suborder of Ophidiiformes, Ophidioidei is oviparous. Recently, the morphological distinct Aphyonidae (Ophidiiformes) were demonstrated to form a monophyletic clade within Bythitidae, and the family was not maintained (Møller et al., 2016). Our results indicate that another family level taxon, Parabrotulidae (including the genera Leucobrotula and Parabrotula), should be considered a monophyletic clade within Bythitidae. ...
Fishes are widely diverse in shape and body size and can quite rapidly undergo these changes. Consequently, some relationships are not clearly resolved with morphological analyses. In the case of fishes of small body size, informative characteristics can be absent due to simplification of body structures. The Parabrotulidae, a small family of diminutive body size consisting of two genera and three species has most recently been classified as either a perciform within the suborder Zoarcoidei or an ophidiiform. Classification of parabrotulids as ophidiiforms has become predominant; however the Parabrotulidae has not yet been investigated in a molecular phylogenetic framework. We examine molecular data from ten genetic loci to more specifically place the Parabrotulidae within the fish tree of life. In a hypothesis testing framework, the Parabrotulidae as a zoarcoid taxon is rejected. Previous identity with zoarcoids due to the one fin ray for each vertebra being present, a characteristic for the Zoarcidae, appears to be an example of convergence. Our results indicate that parabrotulids are viviparous ophidiiforms within the family Bythitidae.
... Here, conventional cytogenetic analyses (Giemsa, C-banding, silver nitrate chromosome staining to evidence nucleolar organiser regions -Ag-NORs, and base-specific fluorochromes staining) and mapping of ribosomal DNA (rDNA) sequences by fluorescent in situ hybridisation (FISH) were performed in four selected species belonging to the genera Kyphosus (15 spp.; Kyphosidae), Amblycirrhitus (5 spp.; Cirrhitidae), Pempheris (69 spp.; Pempheridae) and Stygnobrotula (13 spp.; Bythitidae), all from the Percomorpha group with phylogenetic relationships still under evaluation and consolidation (Møller et al. 2016;Betancur et al. 2017;Ghedotti et al. 2018;Rabosky et al. 2018;Smith et al. 2022). The results expanded the understanding of the karyotype evolution among marine fishes and establish a baseline for future population comparisons. ...
Fishes present an exceptional level of diversification among vertebrates, whose adaptive instructions contained in their genome are physically organised in their chromosomes. Although cytogenetic data are useful to help understand the evolutionary processes, they are restricted or unavailable for many fish families. Cytogenetic characteristics of one Atlantic member of the Kyphosidae, Cirrhitidae, Pempheridae and Bythitidae families-about which little or no prior data is known-are described here. Conventional chromosomal analysis and the mapping of the 18S and 5S ribosomal DNA sequences revealed substantial variations in the diploid number (2n = 38-48) and structure of the chromosomes (FN = 48-84; i.e. number of chromosome arms), as well as in the rDNA distribution (simple, multiple and polymorphic sites). The findings extend the cytogenetic data for reef fish groups across a wider phylogenetic range and reveal the various ways in which karyotype evolution has taken place in the marine environment. ARTICLE HISTORY
... Of the 200+ troglobitic species of fish worldwide, 10 are found in Mexico (Proudlove, 2006), 9 of which are endemic, and 1 of which, Astyanax mexicanus (or A. jordani, depending on the author), is arguably the most popular model in studies of evolutionary cave adaptation mechanisms (Gross, 2012;Miller, 2005). Notably, Mexican-endemic cave fishes comprise representatives from phylogenetically distant lineages, and while the majority can be considered primary freshwater fishes, they also include descendants from brackish/marine ancestors, such as the eleotrid Caecieleotris morrisi (Gobiiformes: Eleotridae) and the viviparous brotula Typhlias pearsei (Ophidiiformes: Dinematichthydae) (Møller et al., 2016;Walsh & Chakrabarty, 2016). In contrast to A. mexicanus, very little is known about most of Mexico's troglobitic ichthyofauna, even on fundamental aspects such as their taxonomy and basic ecology. ...
Four of the 7 species of Rhamdia present in Mexico stand out for being microendemic and also troglobitic, that is, for being restricted to their type-locality caves and for exhibiting a distinctive phenotype characterized by ocular reduction/loss and body depigmentation. Diagnosis and recognition of Mexican troglobitic forms as distinct species, however, appears to be primarily based on their regressive troglomorphic phenotype and highly localized geographic distributions. To test the adequacy of its current taxonomy, we investigated patterns of genetic and phenotypic variation in Mexican troglobitic Rhamdia in a phylogenetic context. Our results indicate that external morphology does not allow for unambiguous differential diagnoses and robust distinction among troglobitic species. Similarly, beyond typical regressive troglomorphic traits, troglobitic species do not differ greatly in external morphology from their most closely related congener, the epigean species Rhamdia laticauda. From a phylogenetic perspective, continued recognition of troglobitic species implies a deep and generalized paraphyly in R. laticauda. Despite the evidence presented herein, we refrain from making nomenclatural decisions until we can unambiguously ascertain that our findings are indeed explained by phylogeographic structure in R. laticauda, instead of by recent divergence and subsequent speciation of cave-dwelling lineages from this widespread epigean species.
... bartschi' (NTUM 10054) examined by Fricke et al. (2014) represented a misidentification. Upon our reexamination, we found that it possesses a combination of characters (a copulatory organ and the caudal fin fused with the dorsal and anal fins) that matches fishes from another ophidiiform family, the Bythitidae Gill, 1861 (Møller et al. 2016). Nevertheless, the six samples of L. bartschi examined in this study were all collected from sites within the reported range of the species (Fig. 1). ...
With six valid species, Luciobrotula is a small genus of the family Ophidiidae, commonly known as cusk-eels. They are benthopelagic fishes occurring at depths ranging from 115–2300 m in the Atlantic, Indian, and Pacific Oceans. Among them, Luciobrotula bartschi is the only known species in the West Pacific. Three specimens of Luciobrotula were collected from the Philippine Sea, Bismarck Sea, and Solomon Sea in the West Pacific during the AURORA, PAPUA NIUGINI, and MADEEP expeditions under the Tropical Deep-Sea Benthos program, and all of them were initially identified as L. bartschi. Subsequent examination with integrative taxonomy indicates that they belong to two distinct species, with the specimen collected from the Solomon Sea representing a new species, which is described here. In terms of morphology, Luciobrotula polylepis sp. nov. differs from its congeners by having a relatively longer lateral line (end of the lateral line below the 33rd dorsal-fin ray) and fewer vertebrae (abdominal vertebrae 13, total vertebrae 50). In the inferred COI gene tree, the two western Pacific species of Luciobrotula do not form a monophyletic group. The genetic K2P distance between the two species is 13.8% on average at the COI locus.
... Core families of cryptobenthic reef fishes (Core CRFs) (see Brandl et al. 2018Brandl et al. , 2019 found in the western Atlantic include the Apogonidae, Blenniidae, Bythitidae, Callionymidae, Chaenopsidae, Dactyloscopidae, Gobiesocidae, Gobiidae, Grammatidae, Labrisomidae, Opistognathidae, Syngnathidae, Tripterygiidae. To these families we added the Dinematichthyidae, which was split from the Bythitidae by Møller et al. (2016) shortly before Brandl et al. (2018) assembled their list of Core CRF families, and contains many shallow, reef-associated species. Species in the list are divided into two depth classes, based on their depth ranges: shallow species are those commonly found above 40 m depth, and deep species are those entirely or largely restricted to depths below 40 m. ...
Sint Eustatius (Statia) is a 21 km ² island situated in the northeastern Caribbean Sea. The most recent published sources of information on that island’s marine fish fauna is in two non-governmental organization reports from 2015–17 related to the formation of a marine reserve. The species-list in the 2017 report was based on field research in 2013–15 using SCUBA diving surveys, shallow “baited underwater video surveys” (BRUVs), and data from fishery surveys and scientific collections over the preceding century. That checklist comprised 304 species of shallow (mostly) and deep-water fishes. In 2017 the Smithsonian Deep Reef Observation Project surveyed deep-reef fishes at Statia using the crewed submersible Curasub. That effort recorded 120 species, including 59 new occurrences records. In March-May 2020, two experienced citizen scientists completed 62 SCUBA dives there and recorded 244 shallow species, 40 of them new records for Statia. The 2017–2020 research effort increased the number of species known from the island by 33.6% to 406. Here we present an updated catalog of that marine fish fauna, including voucher photographs of 280 species recorded there in 2017 and 2020. The Statia reef-fish fauna likely is incompletely documented as it has few small, shallow, cryptobenthic species, which are a major component of the regional fauna. A lack of targeted sampling is probably the major factor explaining that deficit, although a limited range of benthic marine habitats may also be contributing.
... Lucifuga Poey, 1858 is a conspicuous genus of obligate cave-dwelling fishes, currently recognised with six species distributed in Cuba and Bahamas (Nielsen et al. 1999;Møller et al. 2006Møller et al. , 2016; see comparative material). Another nominal species, Lucifuga inopinata Cohen and McCosker, 1998, from off Galapagos Archipelago belongs to another, yet undescribed, genus (Møller unpublished data). ...
Recently, a barcoding study and a molecular phylogenetic analysis of the Cuban species of the cave-fish genus Lucifuga Poey, 1858 revealed the existence of different evolutionary lineages that were previously unknown or passed unnoticed by morphological scrutiny (i.e., cryptic candidate species). In the present study, Lucifuga gibarensis is described as a new species restricted to anchialine caves in the northeastern karst region of the main island. The species was earlier described as a variety of Lucifuga dentata , but since the name was introduced as a variety after 1960, it is deemed to be infrasubspecific and unavailable according to the International Code of Zoological Nomenclature Art. 15.2. The new species differs from L. dentata by pigmented eyes vs. eyes absent and lack of palatine teeth vs. present. Lucifuga gibarensis seems to be most similar to the Bahamian species L. lucayana by showing pigmented eyes, 13 or 14 precaudal vertebrae and ten caudal fin rays. However, differs from it by a larger size of the pigmented eye (1.1–1.9 vs. 0.9–1.0% SL) and number of posterior lateral line neuromasts (30–33 vs. 34–35).
... ). Interestingly, whereas a large number of viviparous brotulas inhabit coral reefs around the world, the few that inhabit continental waters are confined to limestone caves, just like T. pearsei(Møller et al., 2016). From a taxonomic point of view it is worth noting that while originally described in 1938 by Hubbs under the genus Typhlias, subsequent authors synonymized it with Ogilbia and Typhliasina; the latter name dominating recent literature until 2017, when the name Typhlias was resurrected because the names Ogilbia and Typhliasina were unnecessary in the first place(Scharpf, 2017).Although the latest IUCN extinction risk assessment(2019)categorizes T. pearsei as Vulnerable (VU) on the basis of geographic range and quality of habitat, prior evaluations-including North American(Jelks et al., 2008) and local (federal)--listed it as Endangered(SEMARNAT, 2010). ...
... ). Interestingly, whereas a large number of viviparous brotulas inhabit coral reefs around the world, the few that inhabit continental waters are confined to limestone caves, just like T. pearsei(Møller et al., 2016). From a taxonomic point of view it is worth noting that while originally described in 1938 by Hubbs under the genus Typhlias, subsequent authors synonymized it with Ogilbia and Typhliasina; the latter name dominating recent literature until 2017, when the name Typhlias was resurrected because the names Ogilbia and Typhliasina were unnecessary in the first place(Scharpf, 2017).Although the latest IUCN extinction risk assessment(2019)categorizes T. pearsei as Vulnerable (VU) on the basis of geographic range and quality of habitat, prior evaluations-including North American(Jelks et al., 2008) and local (federal)--listed it as Endangered(SEMARNAT, 2010). ...
Mexican freshwater fishes in the IUCN Red List
... ). Interestingly, whereas a large number of viviparous brotulas inhabit coral reefs around the world, the few that inhabit continental waters are confined to limestone caves, just like T. pearsei(Møller et al., 2016). From a taxonomic point of view it is worth noting that while originally described in 1938 by Hubbs under the genus Typhlias, subsequent authors synonymized it with Ogilbia and Typhliasina; the latter name dominating recent literature until 2017, when the name Typhlias was resurrected because the names Ogilbia and Typhliasina were unnecessary in the first place(Scharpf, 2017).Although the latest IUCN extinction risk assessment(2019)categorizes T. pearsei as Vulnerable (VU) on the basis of geographic range and quality of habitat, prior evaluations-including North American(Jelks et al., 2008) and local (federal)--listed it as Endangered(SEMARNAT, 2010). ...
The inland waters of Mexico support a highly diverse group of freshwater fishes with high levels of endemism that occur across a broad range of aquatic habitat types. These aquatic ecosystems provide many direct (e.g., fisheries) and indirect (e.g., agricultural irrigation) benefits to people, and support local livelihoods and economies across Mexico. Freshwater ecosystems are undervalued and receive insufficient funding, political attention and protection. Developing interests and funding for freshwater species conservation is crucial for “bending the curve” to reduce and ultimately reverse freshwater biodiversity declines. Historical disregard for the health and sustainable use of freshwater ecosystems has resulted in alarming rates of loss in the quality and availability of aquatic habitat. This report presents the most recent information on the conservation status and distribution of freshwater fishes in Mexico, and examines the stressors that are driving their declining conservation status. Important conservation actions and considerations are also presented.
Five hundred and thirty-six species of freshwater fishes were assessed against the IUCN Red List Categories and Criteria, representing the most comprehensive assessment of freshwater biodiversity in Mexico to date. This assessment seeks to address the insufficient information available on freshwater fish conservation status, which has resulted in their inadequate representation in environmental planning and management. The full data set, including all species distribution maps, is freely available through the IUCN Red List website (www.iucnredlist.org).
Forty percent of all extant species assessed are threatened with extinction, assuming all Data Deficient species are threatened in the same proportion as those for which enough information was available. The most pervasive threats are related to habitat loss and degradation, which is driven primarily by unsustainable water use and widespread agricultural activity. Excessive extraction of groundwater and diversion of surface water for human consumption, industrial processes, and plantation agriculture has led to widespread flow reductions, reduced water tables, and subsequent drying of aquatic habitat, which is especially prevalent in the arid, endorheic spring systems of northern and central Mexico. Mexico’s vast hydroelectric infrastructure has altered the historical flow regime of many major rivers, blocking natural migration routes and fragmenting subpopulations of native fishes. Agricultural runoff, inadequate wastewater treatment, and industrial discharges have also resulted in increased
levels
... ). Interestingly, whereas a large number of viviparous brotulas inhabit coral reefs around the world, the few that inhabit continental waters are confined to limestone caves, just like T. pearsei(Møller et al., 2016). From a taxonomic point of view it is worth noting that while originally described in 1938 by Hubbs under the genus Typhlias, subsequent authors synonymized it with Ogilbia and Typhliasina; the latter name dominating recent literature until 2017, when the name Typhlias was resurrected because the names Ogilbia and Typhliasina were unnecessary in the first place(Scharpf, 2017).Although the latest IUCN extinction risk assessment(2019)categorizes T. pearsei as Vulnerable (VU) on the basis of geographic range and quality of habitat, prior evaluations-including North American(Jelks et al., 2008) and local (federal)--listed it as Endangered(SEMARNAT, 2010). ...
... ). Interestingly, whereas a large number of viviparous brotulas inhabit coral reefs around the world, the few that inhabit continental waters are confined to limestone caves, just like T. pearsei(Møller et al., 2016). From a taxonomic point of view it is worth noting that while originally described in 1938 by Hubbs under the genus Typhlias, subsequent authors synonymized it with Ogilbia and Typhliasina; the latter name dominating recent literature until 2017, when the name Typhlias was resurrected because the names Ogilbia and Typhliasina were unnecessary in the first place(Scharpf, 2017).Although the latest IUCN extinction risk assessment(2019)categorizes T. pearsei as Vulnerable (VU) on the basis of geographic range and quality of habitat, prior evaluations-including North American(Jelks et al., 2008) and local (federal)--listed it as Endangered(SEMARNAT, 2010). ...
... Comments: Carapidae is now synonymized with Ophidiidae due to phylogenetic nestedness. Recognition of Dinematichthyidae follows PR Møller, SW Knudsen, W Schwarzhans and JG Nielsen [231]; raised from subfamily Dinematichthyinae (formerly Bythitidae). These authors also lumped Aphyonidae with Bythitidae; thus, Aphyonidae is no longer validated. ...
Background
Fish classifications, as those of most other taxonomic groups, are being transformed drastically as new molecular phylogenies provide support for natural groups that were unanticipated by previous studies. A brief review of the main criteria used by ichthyologists to define their classifications during the last 50 years, however, reveals slow progress towards using an explicit phylogenetic framework. Instead, the trend has been to rely, in varying degrees, on deep-rooted anatomical concepts and authority, often mixing taxa with explicit phylogenetic support with arbitrary groupings. Two leading sources in ichthyology frequently used for fish classifications (JS Nelson’s volumes of Fishes of the World and W. Eschmeyer’s Catalog of Fishes) fail to adopt a global phylogenetic framework despite much recent progress made towards the resolution of the fish Tree of Life. The first explicit phylogenetic classification of bony fishes was published in 2013, based on a comprehensive molecular phylogeny (www.deepfin.org). We here update the first version of that classification by incorporating the most recent phylogenetic results.
Results
The updated classification presented here is based on phylogenies inferred using molecular and genomic data for nearly 2000 fishes. A total of 72 orders (and 79 suborders) are recognized in this version, compared with 66 orders in version 1. The phylogeny resolves placement of 410 families, or ~80% of the total of 514 families of bony fishes currently recognized. The ordinal status of 30 percomorph families included in this study, however, remains uncertain (incertae sedis in the series Carangaria, Ovalentaria, or Eupercaria). Comments to support taxonomic decisions and comparisons with conflicting taxonomic groups proposed by others are presented. We also highlight cases were morphological support exist for the groups being classified.
Conclusions
This version of the phylogenetic classification of bony fishes is substantially improved, providing resolution for more taxa than previous versions, based on more densely sampled phylogenetic trees. The classification presented in this study represents, unlike any other, the most up-to-date hypothesis of the Tree of Life of fishes.
Electronic supplementary material
The online version of this article (doi:10.1186/s12862-017-0958-3) contains supplementary material, which is available to authorized users.
... Sequence reads from both directions were assembled and aligned in Geneious v. R7 (Drummond et al., 2010) using MAFFT 6.822 (Katoh and Toh, 2010). Alignments used for the phylogenetic analysis are supplied in the Knudsen et al. (2016). The software DAMBE v. 5.2.57 ...
The order Ophidiiformes is a large but not very well known group of fishes, unique among teleosts for showing high diversity in both deep sea and shallow reef habitats. The current classification includes more than 500 species, 115 genera and four families, based primarily on mode of reproduction: vivipar-ous Aphyonidae and Bythitidae vs oviparous Carapidae and Ophidiidae. Since 2004 we revised the bythi-tid tribe Dinematichthyini, described more than 100 new species and noticed that this group has unique morphological characters, perhaps supporting a higher level of classification than the current status. Here we study the viviparous families phylogenetically with partial mitochondrial (nd4, 16s) and nuclear (Rag1) DNA sequences (2194 bp). We use a fossil calibration of otolith-based taxa to calibrate the age of the clade comprising bythitid and dinematicththyid representatives, together with fossil calibrations adopted from previous phylogenetic studies. The separation of the order into two major lineages, the vivi-parous Bythitoidei and the oviparous Ophidioidei is confirmed. At the familial level, however, a new classification is presented for the viviparous clades, placing Aphyonidae as a derived, pedomorphic member of Bythitidae (new diagnosis provided, 33 genera and 118 species). The current subfamily Brosmophycinae is considered polyphyletic and we propose family status for Dinematichthyidae (25 gen-era, 114 species), supported by unique, morphological synapomorphic characters in the male copulatory apparatus. Previous use of the caudal fin separation or fusion with vertical fins is ambiguous. Age estimates based on calibrated molecular phylogeny agrees with fossil data, giving an origin within the Cretaceous (between 84 and 104 mya) for a common ancestor to Ophidiiformes.
The predominantly Cretaceous gastropod genus Vanikoropsis Meek, 1876 is represented in the Paleocene of Denmark and West Greenland by four species, of which three are established herein as new, viz. Vanikoropsis mortenseni n. sp., Vanikoropsis (s.l.) jakobseni n. sp. and Vanikoropsis (s.l.) bashforthi n. sp. The Danish species was found in a boulder of Kerteminde Marl (Selandian, middle Paleocene) from Gundstrup, while the species from West Greenland were found in the localities Sonja Lens and Qaarsutjægerdal on the Nuussuaq peninsula (late Danian, early Paleocene). The Danish species extends the stratigraphic range of the genus into the middle Paleocene and supports the affinities of the Kerteminde Marl fauna to the Paleocene fauna of West Greenland.
The Ophidiidae is a group of more than 300 species of fishes characterized by elongated, snake‐like bodies and continuous dorsal, anal, and caudal fins. While describing a new species in the genus Monomitopus , we discovered a bilaterally paired fenestra on the dorsomedial surface of the neurocranium. We surveyed the distribution of this fenestra across species of Monomitopus and previously hypothesized allies in the genera Dannevigia , Dicrolene , Homostolus , Neobythites , and Selachophidium , finding variation in its presence and size. We also found a prominent bilaterally paired lateral fenestra and a posterior expansion of the exoccipital in the neurocrania of M. americanus and S. guentheri , with soft tissue connecting the back of the neurocranium to the first epineural and pectoral girdle in S. guentheri . In this study, we describe the distribution of and variation in these features. We integrate morphological characters and DNA data to generate a phylogeny of Monomitopus and allies to understand their relationships and trace the evolutionary history of these novel features. Our results call the monophyly of Monomitopus into question. The presence of the lateral neurocranial fenestra and posterior expansion of the exoccipital support the reclassification of M. americanus as a species of Selachophidium.
Since 2006, an ophidiiform larva with an ovoid body, elongate anterior dorsal-fin ray, and long trailing fleshy filament has been identified as Pycnocraspedum squamipinne. Similarly, the larvae of the ophidiid genus Luciobrotula have been tentatively identified since 1988, with posteriorly displaced dorsal fins and bulging or exterilium guts. However, neither of these larval forms morphologically agree with their adult counterparts. Recently, blackwater divers captured and photographed specimens of larval Luciobrotula and Pycnocraspedum off the coast of Hawaiʻi and Florida, making them available for both morphological and molecular sampling. After examining these larvae and analyzing DNA barcode sequences, as well as a newly captured and sequenced adult of Pycnocraspedum phyllosoma, we revise the previously identified “Pycnocraspedum” larvae to species of Luciobrotula. We describe the larvae of Luciobrotula bartschi and Luciobrotula corethromycter for the first time, highlighting an extraordinary loss of multiple anterior dorsal-fin elements in their ontogeny. We also generate the first DNA sequences for L. corethromycter and P. phyllosoma, adding to the depauperate number of sequences available for ophidiiforms. For the previously identified “Luciobrotula” larvae, neither morphological nor molecular characters provide definitive identification other than recovering them among the Bythitidae. We provide new morphological observations, revised descriptions, and generate a phylogeny of ophidiiform fishes based on COI to place these larvae in a phylogenetic context, prompting further investigation into the relationships of the Ophidiiformes using additional genetic markers. Our study emphasizes the importance of blackwater diving to improving our understanding of marine larval fishes and the need for additional molecular sampling of the diverse order of brotulas, cusk-eels, pearlfishes, and their allies.
In this study we report the first complete and annotated mitochondrial genome of the Mexican blind brotula, Typhlias pearsei, a troglobitic cavefish endemic to the Yucatán peninsula karst aquifer in southeastern Mexico. Genomic sequencing was accomplished via next generation sequencing (NGS). The resulting mitogenome is 16,813 bp long and, as in most vertebrates, consists of a total of 37 genes (13 PCGs, 2 rRNAs, 22 tRNAs) and two non-coding regions (control region and origin of the light strand replication). Other than a rearrangement in the position of two tRNAs (shuffling between tRNA-Ile and tRNA-Gln), the mitogenome of T. pearsei exhibits a genomic composition and organization similar to that of most teleost mitogenomes. Besides offering this valuable genomic resource for future studies, the resulting mitogenome was used in a comparative context to test the current higher-level taxonomy of ophidiiform fishes and to examine the phylogenetic position of T. pearsei among viviparous brotulas. Our phylogenetic results confirm those from the most comprehensive molecular phylogenetic study of the group.
The diversity of bait-attending fishes at lower abyssal and upper hadal depths was assessed using baited cameras in 14 subduction trenches, three fracture zones and two holes, spanning all five oceans. A total of 184 lander deployments from depths >5000 m (plus some additional observation from a submersible) were analysed to resolve the bathymetric extent of fishes and variations between locations. The most common families were the Macrouridae (grenadiers), Ophidiidae (cusk eels) and the Liparidae (snailfishes). Other less common families such as the Zoarcidae (eel pouts), Synphobranchidae (cut-throat eels) are reported, and the Stephanoberycidae (pricklefishes), and Ateleopodidae (jellynoses) were observed for the first time at hadal depths. While acknowledging many cryptic species and difficulty in identifying some groups from video, this study more than doubles the number of species and records of fishes at hadal depths and serves as an updated and illustrated collation of deepest fish records. We also discuss putative influences of temperature and oxygen on the depth range within the liparidae family, of which we found nine new species at hadal depths.
This paper is a checklist of the fishes that have been documented, through both published and unpublished sources, in marine and estuarine waters, and out 200 miles, from the United States-Canadian border on the Beaufort Sea to Cabo San Lucas, Mexico. A minimum of 241 families and 1,644 species are known within this range, including both native and nonnative species. For each of these species, we include maximum size, geographic and depth ranges, whether it is native or nonnative, as well as a brief mention of any taxonomic issues.
In this study, a new species of Pseudogilbia Møller, Schwarzhans & Nielsen 2004 is described based on two male specimens (40–44 mm LS) from shallow reefs of Bahia, Brazil. Pseudogilbia australis sp. nov. is distinguished from its only congener, Pseudogilbia sanblasensis Møller, Schwarzhans & Nielsen 2004 from Caribbean Panama, by having: two lower preopercular pores (vs. one); dorsal‐fin rays 65–67 (vs. 69); anal‐fin rays 51–53 (vs. 56); pectoral‐fin rays 18 (vs. 20); caudal vertebrae 27–28 (vs. 30); pectoral‐fin length 15.0%–15.9% LS (vs. 14.3); pelvic‐fin length 13.5% LS (vs. 16.4) and a different morphology of the male copulatory organ. Pseudogilbia australis sp. nov. is the only dinematichthyid so far recorded in the South Atlantic. An updated diagnosis for the genus is also provided.
The Maastrichtian is an important time interval in the evolution of modern bony fishes. Certain teleost groups that disappeared later during the catastrophic K/Pg boundary extinction event, flourished during this period, while the root stock of other groups that subsequently filled the void and evolved, were already represented. Otoliths constitute an important data set for the reconstruction of extinct teleost faunas and are often found to complement information gained from skeletal remains. Here we describe otoliths obtained from the type area of the Maastrichtian Stage, from various levels within the Maastricht Formation. This assemblage is unique in being preserved as silicified neomorphs and reflects a shallow-marine carbonate environment which is rarely preserved for otolith associations. A total of 49 specimens were recovered from the upper Maastrichtian of the Maastricht Formation, of which 39 could be identified and belong to 15 species, plus one from the overlying Danian. New insight is gained into early gadiform and perciform (sensu lato) diversification. Three new taxa are described: Archaemacruroides vanknippenbergi n. sp. (Gadiformes incertae sedis), Rhinocephalus cretaceus n. sp. (Gadiformes, Merlucciidae) and Cretaserranus maastrichtensis n. gen. et sp. (Perciformes, Serranidae?).
The ichnofossil Lepidenteron provides a unique taphonomic window into the life
habits of a tube-dwelling predator, probably an eunicid polychaete, and its fish prey.
Here we describe a new tube-like ichnofossil Lepidenteron mortenseni n. isp. from the
Kerteminde Marl (100–150 m palaeo-water depth) from the Gundstrup gravel pit
near Odense, Fyn, Denmark. 110 individual tubes were examined which contain fish
remains, including a variety of disarticulated bones and otoliths, by far dominated
by a single gadiform taxon referred herein to as Bobbitichthys n. gen. The isolated
otoliths here associated with disarticulated gadiform bones have previously been
described, from the time equivalent Lellinge Greensand exposed in the Copenhagen area, as Hymenocephalus rosenkrantzi, a grenadier fish (family Macrouridae).
The abundance of associated bones and otoliths in the examined tubes allowed us
to reconstruct part of the cranial configuration of Bobbitichthys rosenkrantzi and to
tentatively interpret it as a stem macrourid. Bobbitichthys rosenkrantzi represents the
earliest grenadier known in the fossil record. Additional, although considerably less
abundant, skeletal remains and otoliths have been tentatively referred to a long-fin
bonefish (family Pterothrissidae, Pterothrissus? conchaeformis), a viviparous brotula
(family Bythitidae, Bidenichthys? lapierrei), a conger eel (family Congridae, possibly
belonging to Rhynchoconger angulosus), and another unidentified gadiform.
Evolution sometimes proceeds by loss, especially when structures and genes become dispensable after an environmental shift relaxes functional constraints. Subterranean vertebrates are outstanding models to analyze this process, and gene decay can serve as a readout. We sought to understand some general principles on the extent and tempo of the decay of genes involved in vision, circadian clock and pigmentation in cavefishes. The analysis of the genomes of two Cuban species belonging to the genus Lucifuga provided evidence for the largest loss of eye-specific genes and non-visual opsin genes reported so far in cavefishes. Comparisons with a recently evolved cave population of Astyanax mexicanus and three species belonging to the Chinese tetraploid genus Sinocyclocheilus revealed the combined effects of the level of eye regression, time and genome ploidy on eye-specific gene pseudogenization. The limited extent of gene decay in all these cavefishes and the very small number of loss of function (LoF) mutations per pseudogene suggest that their eye degeneration may not be very ancient, ranging from early to late Pleistocene. This is in sharp contrast with the identification of several vision genes carrying many LoF mutations in ancient fossorial mammals, further suggesting that blind fishes cannot thrive more than a few million years in cave ecosystems.
Most teleosts are externally fertilizing, with internal fertilization occurring as a relatively rare event. Until now, Euteleosteomorpha is the only teleost cohort known to undergo internal fertilization. In the teleost cohort Otomorpha, it has been recorded the presence of sperm in the ovaries of some species of Characiformes and Siluriformes, but no fertilized eggs have been found so far in the female reproductive tract. It has been presumed that oocytes can be released into the water with associated spermatozoa and only there becomes fertilized, and the term insemination has been used to characterize the strategy adopted by these fish. Here, we present the discovery of the first case of internal fertilization in the teleost cohort Otomorpha, in Compsura heterura (Characiformes: Characidae). In the course of spawning, the eggs form the perivitelline space and the animal and vegetative poles within the ovaries, evidencing oocyte fertilization. The newly spawned eggs then continue to form the animal and vegetative poles and increase the perivitelline space. These eggs are in the zygotic stage. These data indicate that fertilized eggs are only retained for a short period, providing evidence that C. heterura is a zygoparous fish.
During voyages in 2017 off southern and southeastern Australia, the Australian Research Vessel Investigator deployed a series of demersal beam trawls to depths of around 5000 metres. Nineteen specimens of the rarely caught aphyonid-clade of the ophidiiform family Bythitidae, representing five species, were caught. Four of these are new to Australian waters: Barathronus pacificus Nielsen and Eagle, 1974 known from the northeastern and southwestern Pacific Ocean, Paraphyonus bolini (Nielsen, 1974) known from the western Indian and western Pacific Oceans, Paraphyonus rassi (Nielsen, 1975) known from the Atlantic Ocean and Sciadonus pedicellaris Garman, 1899, known from the northeastern Atlantic and northeastern and southwestern Pacific Oceans. Also included are Aphyonus gelatinosus Günther, 1878 known from all oceans including ten specimens from Australian waters, Barathronus maculatus Shcherbachev, 1976 known from South Africa to the westernmost Pacific including 13 specimens from Australian waters, Sciadonus longiventralis Nielsen, 2018 known from the holotype collected off New South Wales and finally Barathronus algrahami n. sp. known from the holotype caught off South Australia and four paratypes from off Taiwan and northern Philippines. Close examination of specimens collected during recent voyages combined with recent and ongoing studies by the first author and DNA COI barcoding analysis enabled an assessment of the aphyonid-clade species hitherto recorded from Australian waters. An identification key to the eight aphyonid clade species known from Australian waters is provided.
Evolution and Development of Fishes - edited by Zerina Johanson January 2019
Many deep-sea fishes have a gelatinous layer, or subdermal extracellular matrix, below the skin or around the spine. We document the distribution of gelatinous tissues across fish families (approx. 200 species in ten orders), then review and investigate their composition and function. Gelatinous tissues from nine species were analysed for water content (96.53 ± 1.78% s.d.), ionic composition, osmolality, protein (0.39 ± 0.23%), lipid (0.69 ± 0.56%) and carbohydrate (0.61 ± 0.28%). Results suggest that gelatinous tissues are mostly extracellular fluid, which may allow animals to grow inexpensively. Further, almost all gelatinous tissues floated in cold seawater, thus their lower density than seawater may contribute to buoyancy in some species. We also propose a new hypothesis: gelatinous tissues, which are inexpensive to grow, may sometimes be a method to increase swimming efficiency by fairing the transition from trunk to tail. Such a layer is particularly prominent in hadal snailfishes (Liparidae); therefore, a robotic snailfish model was designed and constructed to analyse the influence of gelatinous tissues on locomotory performance. The model swam faster with a watery layer, representing gelatinous tissue, around the tail than without. Results suggest that the tissues may, in addition to providing buoyancy and low-cost growth, aid deep-sea fish locomotion.
Aphyonids are poorly-known, live-bearing brotulas (Ophidiiformes, Bythitidae) that until recently were considered to be in a distinct family, Aphyonidae. A single, ca. 9.3 cm total length aphyonid observed during a remotely-operated vehicle survey in the Mariana Archipelago at 2504.2 m on Explorer Ridge (20.68152°N, 145.08750°E) is the first seen alive in its natural habitat. Collection to verify its identification was not possible, but based on observations it was a species of either Barathronus or Nybelinella. The fish swam 1–10 cm over sediment between rocks and small boulders on a 45° talus slope. Swimming speeds were consistently slow, 0.33 ± 0.15 body lengths per second, and the fish appeared to be neutrally buoyant. Although there are few other records of aphyonid-clade fishes in the Pacific away from continental margins, this observation suggests that they will be found elsewhere in the basin when appropriate methods are used to detect these small fishes in the high-relief, rugose habitats of central Pacific oceanic islands and seamounts.
The genus Nybelinella belongs to the aphyonid clade within the Bythitidae. This mainly abyssal genus is known from 30 specimens. The present revision is based on 24 specimens, of which a scientific examination of four specimens has been published earlier. As a consequence, the generic diagnosis from Nielsen et al. (1999) is here modified. Of the 24 specimens 22 are referred to N. erikssoni (Nybelin, 1957), one to N. brevidorsalis Shcherbachev, 1976 and one to a new species, N. brevianalis n. sp., herein described.
Plagioporus hageli n. sp. is described from the intestine of Oncorhynchus mykiss (Walbaum) collected from the River Yuba, California, USA. Of the accepted, nominal species of Plagioporus Stafford, 1904 from the Nearctic, the new species is morphologically similar to three intestinal species from the western USA parasitising diadromous fishes, including Plagioporus shawi (McIntosh, 1939), Plagioporus kolipinskii Tracey, Choudhury, Cheng & Ghosh, 2009 and Plagioporus siliculus Sinitsin, 1931, and is also similar to Plagioporus serotinus Stafford, 1904 from catostomids from eastern Canada. Plagioporus hageli n. sp. is distinguished from the former three species in lacking a dorsal vitelline field and from the latter species in having a consistent interruption in the distribution of the vitellarium at the level of the ventral sucker. The new species is also morphologically similar to an unnamed species of Plagioporus and a species misidentified as ‘Plagioporus angusticolle’ that were collected from California, but it is easily distinguished from both in its shorter body length. To estimate the placement of the new species within Plagioporus and within the Opecoelidae Ozaki, 1925, we conducted a Bayesian inference (BI) analysis of partial 28S rDNA sequence data that included sequences from Plagioporus hageli n. sp., five other species of Plagioporus, three species of Neoplagioporus Shimazu, 1990, including the type-species, Neoplagioporus zacconis (Yamaguti, 1934), two species of Urorchis Ozaki, 1927 (including the type-species, Urorchis goro Ozaki, 1927) and sequences of 42 opecoelid species obtained from GenBank. Our phylogenetic analysis revealed (i) plagioporines parasitising freshwater hosts form a monophyletic group; (ii) Plagiocirrus loboides Curran, Overstreet & Tkach, 2007 nested within the rest of the members of Plagioporus; (iii) the new species was closer to Plagiocirrus loboides than to Plagioporus shawi, the other salmonid parasite included in our analysis; (iv) P. shawi was the poorly supported sister to its congeners; (v) Neoplagioporus elongatus (Goto & Ozaki, 1930) Shimazu, 1990 was closer to the two species of Urorchis than to the other two species of Neoplagioporus; and (vi) the paraphyly of the Plagioporinae Manter, 1947 was reinforced. Based on 28S rDNA sequence data and our BI analysis, we propose Plagioporus loboides (Curran, Overstreet & Tkach, 2007) n. comb., and amend Plagioporus accordingly. This analysis represents the first phylogenetic study of the opecoelids that estimates the interrelationships of the Plagioporinae that includes a member of Plagioporus.
This article comprise the data related to the research article “A new classification of viviparous brotulas (Bythitidae) – with family status for Dinematichthyidae – based on molecular, morphological and fossil data” [1], and makes it possible to explore and reproduce the topologies that allowed [1] to infer the relationship between the families Bythitidae and Dinematichthyidae. The supplementary data also holds nexus-input files for the Bayesian analysis and the ‘.xml’-input files – with and without nucleotide data – that are used in the fossil-calibrated phylogenetic analysis with a relaxed clock model. The resulting topologies are provided as ‘.new’-files together with a characters matrix file for traits to trace across the inferred phylogenies.
Material of three similar and probably related genera of the viviparous ophidiiform family, Bythitidae, has been studied.The monotypic Hastatobythites is only known from the original two specimens; re-examination of the paratype and infor-mation of the holotype clearly demonstrates the validity of the genus. The revision of Saccogaster (Cohen & Nielsen1972) was based on 15 specimens. Since then 29 additional specimens have been collected representing 11 species, threeof which are here described: S. brayae, horrida and nikoliviae. Three of the 11 Saccogaster species, S. melanomycter, S.normae and S. rhamphidognatha, differ so much from the remaining eight that a new genus, Parasaccogaster, is de-scribed. The main diagnostic characters used for the three genera are: A pair of spines on frontal plate behind eyes, spineson snout, length of gill filaments on anterior arch, number and length of developed gill rakers, size of gill opening, thick-ness of skin, head pores, otolith morphology, color marks on head, neuromasts on head and head morphometrics, fin ray counts.
Background
Fish classifications, as those of most other taxonomic groups, are being transformed drastically as new molecular phylogenies provide support for natural groups that were unanticipated by previous studies. A brief review of the main criteria used by ichthyologists to define their classifications during the last 50 years, however, reveals slow progress towards using an explicit phylogenetic framework. Instead, the trend has been to rely, in varying degrees, on deep-rooted anatomical concepts and authority, often mixing taxa with explicit phylogenetic support with arbitrary groupings. Two leading sources in ichthyology frequently used for fish classifications (JS Nelson’s volumes of Fishes of the World and W. Eschmeyer’s Catalog of Fishes) fail to adopt a global phylogenetic framework despite much recent progress made towards the resolution of the fish Tree of Life. The first explicit phylogenetic classification of bony fishes was published in 2013, based on a comprehensive molecular phylogeny (www.deepfin.org). We here update the first version of that classification by incorporating the most recent phylogenetic results.
Results
The updated classification presented here is based on phylogenies inferred using molecular and genomic data for nearly 2000 fishes. A total of 72 orders (and 79 suborders) are recognized in this version, compared with 66 orders in version 1. The phylogeny resolves placement of 410 families, or ~80% of the total of 514 families of bony fishes currently recognized. The ordinal status of 30 percomorph families included in this study, however, remains uncertain (incertae sedis in the series Carangaria, Ovalentaria, or Eupercaria). Comments to support taxonomic decisions and comparisons with conflicting taxonomic groups proposed by others are presented. We also highlight cases were morphological support exist for the groups being classified.
Conclusions
This version of the phylogenetic classification of bony fishes is substantially improved, providing resolution for more taxa than previous versions, based on more densely sampled phylogenetic trees. The classification presented in this study represents, unlike any other, the most up-to-date hypothesis of the Tree of Life of fishes.
Electronic supplementary material
The online version of this article (doi:10.1186/s12862-017-0958-3) contains supplementary material, which is available to authorized users.
The Catalog of Fishes covers more than 61,700 species and subspecies, over 11,000 genera and subgenera, and includes in excess of 34,000 bibliographic references. Entries for species, for example, consist of species/subspecies name, genus, author, date, publication, pages, figures, type locality, location of type specimen(s), current status (with references), family/subfamily, and important publication, taxonomic, or nomenclatural notes. Nearly all original descriptions have been examined, and much effort has gone into determining the location of type specimens.
Online version: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp
Please visit the authors' website for this book: https://sites.google.com/view/fishes-of-the-world-5/welcome.
Fishes of the World, Fifth Edition is the only modern, phylogenetically based classification of the world’s fishes. The updated text offers new phylogenetic diagrams that clarify the relationships among fish groups, as well as cutting-edge global knowledge that brings this classic reference up to date. With this resource, you can classify orders, families, and genera of fishes, understand the connections among fish groups, organize fishes in their evolutionary context, and imagine new areas of research. To further assist your work, this text provides representative drawings, many of them new, for most families of fishes, allowing you to make visual connections to the information as you read. It also contains many references to the classical as well as the most up-to-date literature on fish relationships, based on both morphology and molecular biology.
The study of fishes is one that certainly requires dedication—and access to reliable, accurate information. With more than 30,000 known species of sharks, rays, and bony fishes, both lobe-finned and ray-finned, you will need to master your area of study with the assistance of the best reference materials available. This text will help you bring your knowledge of fishes to the next level.
- Explore the anatomical characteristics, distribution, common and scientific names, and phylogenetic relationships of fishes
- Access biological and anatomical information on more than 515 families of living fishes
- Better appreciate the complexities and controversies behind the modern view of fish relationships
- Refer to an extensive bibliography, which points you in the direction of additional, valuable, and up-to-date information, much of it published within the last few years.
711 pages, Index, Bibliography
A comparison of the bythitids Fiordichthys slartibartfasti Paulin, 1995 and the two species of Melodichthys, paxtoni and hadrocephalus both Nielsen & Cohen (1986), clearly shows that M. paxtoni is much closer to F. slartibartfasti than to M. hadrocephalus. Consequently, M. paxtoni is reassigned to Fiordichthys. By examination of the copulatory organ it furthermore appeared that Fiordichthys belongs to the brosmophycine tribe Brosmophycini rather than to Dinematichthyini where it was originally referred.
Cusk-eels of the order Ophidiiformes are a morphologically diverse assemblage of eel-like, elongate, posteriorly tapering percomorph fishes that occur worldwide in marine waters, from tropical reef areas to the deep sea. The about 400 extant and fossil species included in the ophidiiform clade are arranged into two main lineages, Bythitoidei and Ophidioidei, based on reproductive biology and the position of the anterior nostrils. The anatomy and phylogenetic relationships of these fishes are largely unknown, and the fossil record has not provided substantial information about the earliest phases of their evolutionary history. †Pastorius methenyi, new genus and species, the oldest member of the Ophidiiformes based on articulated skeletal remains, is described herein based on a single specimen collected from the Campanian-Maastrichtian organic-rich laminated limestone of the Liburnica Formation outcropping near the village of Trebiciano, north-eastern Italy. The comparative analysis of osteological and meristic features indicates that †Pastorius methenyi is characterized by at least one of the probable ophidiiform synapomorphies (exclusion of the supraoccipital from the posterior cranial margin by substantial posterodorsal extension of the exoccipitals) and exhibits a unique combination of characters, including a posteriorly broadly expanded maxilla; supramaxilla present; eight branchiostegals; 39 vertebrae; first neural spine shorter than those following; neural arch of first vertebra feebly connected to the first vertebral centrum though a narrow pedestal of bone; anterior abdominal vertebrae ostensibly lacking expanded ribs; caudal skeleton with ostensibly fused first preural, first ural centrum, first uroneural, and ventral hypural plate, and ostensibly fused second ural centrum and dorsal hypural plate, autogenous parhypural, and two epurals; caudal fin free, with 13 rays; a single ossified supraneural located in front of the second neural spine; and notably reduced number of dorsal- and anal-fin rays. †Pastorius is placed as the sister-group of all recent bythitoids, even if some features might indicate that it represents the sister-group of all ophidiiforms. †Pastorius provides the first unequivocal evidence that percomorphs with very elongate and compressed bodies were in existence in the Cretaceous, indicating that this group was characterized by a very high disparity and a vast diversification of bodyplans well before the Cretaceous-Paleogene extinction. © 2015 by the American Society of Ichthyologists and Herpetologists.
Percomorphs are a large and diverse group of spiny-finned fishes that have come to be known as the "bush at the top" due to their persistent lack of phylogenetic resolution. Recently, the broader E-uteleost Tree of Life Project (EToL) inferred a well-supported phylogenetic hypothesis that groups the diversity of percomorphs into nine well-supported series (supraordinal groups): Ophidiaria, Batrachoidaria, Gobiaria, Syngnatharia, Pelagiaria, Anabantaria, Carangaria, Ovalentaria, and Eupercaria. The EToL also provided, for the first time, a monophyletic definition of Perciformes - the largest order of vertebrates. Despite significant progress made in accommodating the diversity of percomorph taxa into major clades, some 62 families (most previously placed in "Perciformes", as traditionally defined) were not examined by the EToL. Here, we provide evidence for the phylogenetic affinities of 10 of those 62 families, seven of which have largely remained enigmatic. This expanded taxonomic sampling also provides further support for the nine EToL supraordinal series. We examined sequences from 21 genes previously used by the EToL and added two fast-evolving mitochondrial markers in an attempt to increase resolution within the rapid percomorph radiations. We restricted the taxonomic sampling to 1229 percomorph species, including expanded sampling from recent studies. Results of maximum likelihood analysis revealed that bathyclupeids (Bathyclupeidae), galjoen fishes (Dichistiidae), kelpfishes (Chironemidae), marblefishes (Aplodactylidae), trumpeters (Latridae), barbeled grunters (Hapalogenyidae), slopefishes (Symphysanodontidae), and picarel porgies (formerly Centracanthidae) are members of the series Eupercaria ("new bush at the top"). The picarel porgies and porgies (Sparidae) are now placed in the same family (Sparidae). Our analyses suggest a close affinity between the orders Spariformes (including Lethrinidae, Nemipteridae and Sparidae) and Lobotiformes (including the tripletails or Lobotidae, the barbeled grunters, and tigerperches or Datnioididae), albeit support for this group is low. None of the newly examined families belong in the order Perciformes, as recently defined. Finally, we confirm results from other recent studies that place the Australasian salmons (Arripidae) within Pelagiaria, and the false trevallies (Lactariidae) close to flatfishes, jacks, and trevallies, within Carangaria.
A comprehensive relational database on pre-Quaternary Phanerozoic reefs is described. The database contains coded and standardized information on position/paleoposition, age, reef type, dimensions, environmental setting, paleontological and petrographi-cal features, and reservoir quality of Phanerozoic reefs. At the time of submission, 3050 reef sites were included in the database. True reefs, mounds, and biostromes are considered. Although the database is incomplete, both in the quality of information provided for each reef and the quantity of reefs, the information contained is thought to reflect actual trends in the reef ecosystem. The reliability of statistical analyses based on the database varies through geologic time depending on the quantity and quality of data in each time slice but is reasonable on average.
During the Danish Galathea 3 Expedition, leg 10, 14–29 December 2006, 29 species of bottom or nearbottom
deep-water fishes were caught at depths between 440 and 4450 meters in the Solomon Sea.
Sixteen of these belong to the order Ophidiiformes, and are new records for the Solomon Sea. Several
of the species are hitherto known only from very few specimens and three species are new to science:
Barathronus solomonensis n. sp., Bellottia galatheae n. sp. and Tuamotuichthys schwarzhansi n. sp.
The order Ophidiiformes is a large but not very well known group of fishes, unique among teleosts for showing high diversity in both deep sea and shallow reef habitats. The current classification includes more than 500 species, 115 genera and four families, based primarily on mode of reproduction: vivipar-ous Aphyonidae and Bythitidae vs oviparous Carapidae and Ophidiidae. Since 2004 we revised the bythi-tid tribe Dinematichthyini, described more than 100 new species and noticed that this group has unique morphological characters, perhaps supporting a higher level of classification than the current status. Here we study the viviparous families phylogenetically with partial mitochondrial (nd4, 16s) and nuclear (Rag1) DNA sequences (2194 bp). We use a fossil calibration of otolith-based taxa to calibrate the age of the clade comprising bythitid and dinematicththyid representatives, together with fossil calibrations adopted from previous phylogenetic studies. The separation of the order into two major lineages, the vivi-parous Bythitoidei and the oviparous Ophidioidei is confirmed. At the familial level, however, a new classification is presented for the viviparous clades, placing Aphyonidae as a derived, pedomorphic member of Bythitidae (new diagnosis provided, 33 genera and 118 species). The current subfamily Brosmophycinae is considered polyphyletic and we propose family status for Dinematichthyidae (25 gen-era, 114 species), supported by unique, morphological synapomorphic characters in the male copulatory apparatus. Previous use of the caudal fin separation or fusion with vertical fins is ambiguous. Age estimates based on calibrated molecular phylogeny agrees with fossil data, giving an origin within the Cretaceous (between 84 and 104 mya) for a common ancestor to Ophidiiformes.
This book is aimed at the amateur fossil collector and is designed to provide a pocket field guide to the range of macrofossils found in the British Chalk. The common species likely to be encountered are described in turn for all the major groups with the exception of the serpulid worms and corals. The book deals in turn with sponges; bryozoans; brachiopods; bivalves; gastropods; ammonites; belemnites; crustaceans; echinoderms; fishes and reptiles. Useful monographs relating to a particular group are listed at the start of the chapter. Almost 400 Chalk fossils are illustrated, and for each entry there is a brief description to aid in identification and a description of the stratigraphic range. Similar and easily confused species are compared and contrasted in the text.-A.W.Hall
An otolith fauna of 24 species was found in the upper part of the Bassevelde Sand. Seven new species and four new genera are described.-from Author
Exclusively available online, http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp
After the global Cretaceous–Paleogene boundary impact catastrophy, planktonic foraminifera and nannofossils start new evolutionary trends, and mammals appear on Earth; global warming episode occurs at the Paleocene–Eocene boundary and significant cooling trends develop in later Paleogene in preparation for Modern life and climate. Orbital tuning of deep-marine cyclic sedimentation patterns, calibrated to the geomagnetic polarity and biostratigraphic scales, have the potential to elevate the Paleogene time scale to the level of resolution of the Neogene. HISTORY AND SUBDIVISIONS Overview of the Paleogene The Cenozoic Era (Phillips, 1841, originally “Cainozoic,” from kainos = new and zoon = animal) is subdivided into the Paleogene (palaios = old, genos = birth) and Neogene periods. The use of “Tertiary” (Arduino, 1759) and “Quaternary” (Desnoyers, 1829) is not recommended, being equally antiquated terms such as Primary and Secondary that have fallen into disuse in the twentieth century. Naumann (1866) combined in his “Paleogen Stufe,” the Eocene and Oligocene, as opposed to the “Neogen Stufe” of Hörnes (1853) which included not only the miocene and the Pliocene, but also fauna of the Pleistocene (see Chapter 21).
The cosmopolitan, deep sea, aphyonid genus Aphyonus is known from less than 100 specimens. The type species A. gelatinosus Günther, 1878 and three additional valid species, A. brevidorsalis Nielsen, 1969, A. bolini Nielsen, 1974, and A. rassi Nielsen, 1975 were all based on single specimens. Since then several specimens have been caught of which 52 are examined for the present revision. Most of the specimens are referred to A. gelatinosus but also to A. bolini and A. rassi. A result of the enlarged material is that the type species, A. gelatinosus, is found to differ so much from the remaining species that a new genus, Paraphyonus, is established for these species. Furthermore two new species of Paraphyonus are here described, P. iselini based on six specimens from the tropical northwestern Atlantic Ocean and P. merretti based on three specimens from the northeastern Atlantic Ocean. The present knowledge of the variation of the Paraphyonus species makes it relevant to transfer Barathronus solomonensis Nielsen & Møller, 2008 to this genus.
A successor to A Geologic Time Scale 1989 (Cambridge, 1990), this volume introduces the theory and methodology behind the construction of the new time scale, before presenting the scale itself in extensive detail. An international team of over forty stratigraphic experts develops the most up-to-date international stratigraphic framework for the Precambrian and Phanerozoic eras. A large wallchart (not available for eBook) summarizing the time scale at the back of the book completes this invaluable reference for researchers and students.
