Taxonomy Of Fishes Research Articles

There is increasing evidence that species diversity is underestimated in the current taxonomy of widespread freshwater fishes. The bagrid species T. albomarginatus s.l. is mainly distributed in the lowlands of South China, as currently identified. A total of 40 localities (including the type locality), which covers most of its known range, were sampled. Molecular phylogenetic analyses based on concatenated mtDNA and nuclear genes recover nine highly supported lineages clustering into eight geographic populations. The integration of molecular evidence, morphological data, and geographic distribution demonstrates the delineation of T. albomarginatus s.l. as eight putative species. Four species, namely, T. albomarginatus, T. lani, T. analis, and T. zhangfei sp. nov. and the T. similis complex are taxonomically recognized herein. Moreover, T. zhangfei sp. nov. comprises two genetically distinct lineages with no morphological and geographical difference. This study also reveals aspects of estimation of divergence time, distribution, and ecological adaption within the T. albomarginatus group. The unraveling of the hidden species diversity of this lowland bagrid fish highlights the need for not only the molecular scrutiny of widely distributed species of South China but also the adjustment of current biodiversity conservation strategies to protect the largely overlooked diversity of fishes from low-elevation rapids.

Morphology-based taxonomy of freshwater fish is effective when there are representative specimens covering large regions. However, in Sundaland, where the presence of cryptic species is high, the technique has its limitations. This is compounded by uncritical descriptions of holotypes in old literature. We demonstrate the problem using Barbodes binotatus first described from an ink drawing. Several species in the Barbodes genus of Sundaland exhibit morphological similarity to B. binotatus. We applied new DNA sequences of 16S, cytochrome c oxidase subunit I (COI), cytochrome b (Cytb) and recombination-activating gene 1 (RAG1), and pigmentation markers to clarify species complex boundaries in the Malay Peninsula, namely B. aff. binotatus "Malay Peninsula", Barbodes cf. banksi and Barbodes rhombeus. Results suggest B. binotatus-like specimens in the Malay Peninsula are B. rhombeus based on a threshold of 3% COI genetic divergence. B. aff. binotatus recorded in Sumatra, Borneo and the Philippines are likely valid but undescribed species. However, if the 2% COI threshold is applied, some populations in the northern Malay Peninsula would qualify as new and undescribed species. The implications of the 2% threshold and the likelihood of "grey zone" incipient populations are discussed. We further found a rapid visual method, not reported previously, to delineate B. aff. binotatus and B. cf. banksi, but it requires further validation. Additionally, we offer fresh perspectives by discussing the roles of biological species concept, morphological species concept, genetic species concept and mate recognition concept in the B. binotatus complex. Our findings reinforce the standpoint that species delineation is not entirely a binary process, but there is a spectrum to consider, especially in biogeography intersection regions.

Taxonomic identification of fishes is essential in conservation study and to understand their role in an aquatic ecosystem. The study of scale morphology provides new and useful information in the field of the taxonomy of fish and paleontological analysis. The purpose of this study was to determine the scale morphology and the surface ultra-structural details like circuli, radii and focus. Other structures like tubercles, denticles, canals, chromatophores, ctenii were also noted with specifications, arrangement and numbers, on the scales. The teleost species Notopterus kapirat and Etroplus suratensis were selected in this study from the Godavari river basin in Maharashtra. Other than morphological characters using phase-contrast microscopy and SEM the microphotographs of selected characters of the scales were noted. From the result, it was concluded that fish scales have numerous hidden detail in their structures and they are a new advanced tool in fish systematics even after not getting the whole fish sample but the availability of scales only is enough.

Abstract We provide our perspective on the species-level taxonomy of notothenioid fishes, the dominant component of the fish fauna of Antarctica. There are 140 species in 45 genera, an increase of 15% since the previous summary in 2000. Biogeographically, 30 species are non-Antarctic, 33 are sub-Antarctic and 77 are Antarctic. The checklist is documented with footnotes that provide the rationale for our decisions. Supplementary Material provides additional details for our decisions on two species ofPogonophryne.

The tridentigerine genus Pseudogobius is widespread, from temperate to tropical areas of the Indo-west Pacific. A morphological review of the genus was carried out, with the initial focus on South-east Asian and Australian species. There are about 21 nominal species in the genus; however, the type specimens for some nominal species are missing. Our work recognises 15 valid species so far, including seven new species, which are described herein: P. aquilonius n. sp., P. cinctus n. sp., P. eos n. sp., P. hoesei n. sp., P. jeffi n. sp., P. rhizophora n. sp. and P. verticalis n. sp. We also conclude that P. poicilosoma (Bleeker, 1849) is the senior synonym of P. javanicus (Bleeker, 1856). Pseudogobius poicilosoma, P. gastrospilos (Bleeker, 1853) and P. javanicus are accepted here as conspecific, although the types are in poor condition (note that all three names were given to specimens collected within close proximity to each other in coastal Java, Indonesia). A key to valid species is presented. The revision benefited from an adaptive feedback loop with companion genetic analyses, with the most comprehensive data available for the Australian region. Broader preliminary genetic data suggest the potential for recognition of additional cryptic species, with the current study providing a platform for future systematic work. Pseudogobius are a prominent part of estuarine biodiversity in the Indo-west Pacific, and this study helps to highlight the need to better understand the taxonomy and conservation requirements of cryptobenthic fishes.

Urotrygon chilensis (Günther, 1872) was described based on a single specimen acquired by the British Museum of Natural History, London, from the Johan Cesar Godeffroy Museum in Hamburg. This medium-sized, benthic stingray is found along the eastern Pacific shelf (distance ranging almost 7000 km). During the last century, it has been frequently mentioned in the taxonomy and biogeography of Chile's marine fishes. However, since the original description in 1872, no other record of this species has been reported from Chilean waters. In this study, the historical presence of U. chilensis in Chile was confirmed based on three mature male specimens held at the Zoological Museum of the University of Hamburg (ZMH) collected in Taltal Harbour (Chile) in July 1894. According to the International Code of Zoological Nomenclature guidelines, we propose Taltal Harbour as the type locality of U. chilensis. Additionally, we conduct a historical review to determine how Albert Günther might have obtained the holotype. The discovery of these specimens catalogued in the fish collection at the ZMH is a demonstration of the important role that natural history museums play in documenting biodiversity patterns. The geographical distribution of U. chilensis is extended to the Central Chile marine ecoregion, approximately 1,500 km southward, from records in available databases. However, 126 years after its last recorded capture off Chile's coast, the historical presence of U. chilensis at such southern latitudes seems to reflect vagrancy in response to weather conditions.

Abstract Dorothy Rayner was one of the first women to be appointed to a tenured academic post in any English university geology department, joining the Geology Department of the University of Leeds in 1939 and serving for 38 years to her retirement in 1977. She had two very important early influences in her life. The first was her family, with its tradition through several generations of doctors, scientists, engineers, mathematicians, radical politics and social activism. The other was her earlier education, particularly her 7 years at the very influential Bedales School, the first of what were to become known in the twentieth century as ‘progressive’ schools. After gaining a First at Girton College in the Cambridge Natural Sciences Tripos, she undertook ground-breaking research on the taxonomy and neural systems of Jurassic fishes, for which she was awarded a Cambridge PhD in 1938, soon after which she was appointed Assistant Lecturer in Geology at Leeds. In addition to an always very heavy teaching load, she continued with a broad range of research, including further work on fossil vertebrates, and the stratigraphy of first the north of England and then the whole of the British Isles. She was also an outstanding Editor, and then President, of the Yorkshire Geological Society.

Sculpin fishes belonging to the family Cottidae represent a large and complex group, inhabiting a wide range of freshwater, brackish-water, and marine environments. Numerous studies based on analysis of their morphology and genetic makeup frequently provided controversial results. In the present work, we sequenced complete mitochondrial (mt) genomes and fragments of nuclear ribosomal DNA (rDNA) of the fourhorn sculpin Myoxocephalus quadricornis and some related cottids to increase the power of phylogenetic and taxonomic analyses of this complex fish group. A comparison of the My. quadricornis mt genomes obtained by us with other complete mt genomes available in GenBank has revealed a surprisingly low divergence (3.06 ± 0.12%) with Megalocottus platycephalus and, at the same time, a significantly higher divergence (7.89 ± 0.16%) with the species of the genus Myoxocephalus. Correspondingly, phylogenetic analyses have shown that My. quadricornis is clustered with Me. platycephalus but not with the Myoxocephalus species. Completely consistent patterns of divergence and tree topologies have been obtained based on nuclear rDNA. Thus, the multi-gene data in the present work indicates obvious contradictions in the relationships between the Myoxocephalus and Megalocottus species studied. An extensive phylogenetic analysis has provided evidence for a closer affinity of My. quadricornis with the species of the genus Megalocottus than with the species of the genus Myoxocephalus. A recombination analysis, along with the additional GenBank data, excludes introgression and/or incorrect taxonomic identification as the possible causative factors responsible for the observed closer affinity between the two species from different genera. The above facts necessitate realignment of the genera Myoxocephalus and Megalocottus. The genetic data supports the two recognized genera, Myoxocephalus and Megalocottus, but suggests changing their compositions through transferring My. quadricornis to the genus Megalocottus. The results of the present study resolve the relationships within a complex group of sculpin fishes and show a promising approach to phylogenetic systematics (as a key organizing principle in biodiversity research) for a better understanding of the taxonomy and evolution of fishes and for supplying relevant information to address various fish biodiversity conservation and management issues.

Purpose : Fish species of the family Channidae, commonly known as snakeheads, represent biggest and most caught native freshwater species in Sri Lanka. Despite importance for biodiversity and fisheries in Sri Lanka, members of this family are one of the least studied on taxonomic status and geographic distribution.Research Method : As an initial step of a study to revise the taxonomy and biogeography of freshwater fish in the family Channidae based on molecular phylogenetic and morphological relationships and biogeographical affinities, authors reviewed all the available published information and examined the specimens available at the National Museum of Sri Lanka.Findings : Six valid species have been recorded; Channa ara (Deraniyagala, 1945), C. marulius (Hamilton, 1822) C. kelaartii (Gunther,1861), C. orientalis Bloch and Schneider 1801 C. punctata (Bloch, 1794) and C. striata (Bloch, 1793). Current review suggests the exiting knowledge on the phylogeny and biogeography of Channidae in Sri Lanka is far from complete, identifying specific gaps to be prioritized in future research.Limitations : Current regional studies on the family Chanidae highlight the importance of a complete systematic revision of Sri Lankan species with an integrative approach. Literature review shows the necessity of a fresh analysis on the distribution data with ecological niche modeling and molecular phylogenetic studies to understand biogeographical and evolutionary history of the family.Originality / Value : Provides a consolidated account of the current knowledge on the taxonomy and biogeography of the Sri Lankan members of the family Channidae.

The taxonomy and classification of the microcanthid fish genus Microcanthus Swainson has been a subject of contention dating back to the 19th century. Its allopatric, disjunct anti-equatorial distribution across the Indo-West Pacific has resulted in the recognition of several nominal taxa, though these have been widely regarded as synonyms of Microcanthus strigatus (Cuvier). Following the results published in a companion study elsewhere by the authors, the taxonomy of Microcanthus and the validity of these nominal synonyms are herewith revised. Microcanthus strigatus is redescribed on the basis of 66 specimens from East Asia, Hawaii and Western Australia, and M. joyceae is resurrected and redescribed on the basis of 25 specimens from eastern Australia and the southwest Pacific. Microcanthus differs from other microcanthid genera in having the following combination of characters: dorsal-fin rays XI,15-17 (usually XI,16); anal-fin rays III,13-15 (usually III,14); pectoral-fin rays 15-17 (usually 16); scales ctenoid with ctenial bases present; lateral-line scales partially or heavily obscured by adjacent scales; and body pale in preservation with five horizontal dark stripes reaching the posterior edges of dorsal and anal fins, and base of caudal fin. The review is accompanied by a key to the genera of Microcanthidae.

In order to improve our understanding of the characterization of Cheilinus fasciatus mitogenome and the classification status in Labridae, the full-length mtDNA of C. fasciatus was sequenced, which is 16,872 bp in length with the higher A + T content (53%). It is composed of 37 typical vertebrate mitochondrial genes and a noncoding control region (D-loop). Except for the ND6 gene and eight tRNAs, the rest of the genes are encoded on the heavy strand (H-strand). Subsequent phylogenetic analyses support that C. fasciatus belongs to the genus Cheilinus, which is closely related to two genera (Chlorurus and Scarus). The present study will provide important information for future understanding evolutionary theory, population molecular genetics and biological taxonomy of labrid fish.

The Australian Mesozoic fish fauna is considered to be depauperate in comparison with fish faunas in the Northern Hemisphere. However, due to its geographical location as a potential radiation center in the Southern Hemisphere, Australia’s Mesozoic fish fauna is important for understanding fish radiations. Most of the modern fish groups originated during the Mesozoic, but the first records of a modern fish fauna (freshwater and marine) in Australia does not occur until the lower Paleogene. Here, we review all known fossil fish-bearing localities from the Mesozoic of Australia, to improve the understanding of the record. The apparent low Australian Mesozoic fish diversity is likely due to its understudied status of the constituent fossils rather than to a depauperate record. In addition, we review recent work with the aim of placing the Australian Mesozoic fish fauna in a global context. We review the taxonomy of Australian fossil fishes and conclude that the assignments of many actinopterygians need major revision within a modern phylogenetic context. The vast majority of chondrichthyans are yet to be formally described; to the contrary all of the known lungfish specimens have been described. This study considers the microscopic and fragmented remains of Mesozoic fish already found in Australia, allowing a more complete view of the diversity of the fishes that once inhabited this continent.Rodney W. Berrell [r.berrell@postgrad.curtin.edu.au], School of Earth and Planetary Sciences, Curtin University, Kent Street, Bentley, Western Australia, 6102, Australia; Catherine Boisvert [Catherine.Boisvert@curtin.edu.au], School of Molecular and Life Sciences (MLS), Curtin University, Kent Street, Bentley, Western Australia, 6102, Australia; Kate Trinajstic [K.Trinajstic@curtin.edu.au], School of Molecular and Life Sciences (MLS), Curtin University, Kent Street, Bentley, Western Australia, 6102, Australia; Mikael Siversson# [mikael.siversson@museum.wa.gov.au], Department of Earth and Planetary Sciences, Western Australian Museum, 49 Kew Street, Welshpool, Western Australia, 6106, Australia; Jesús Alvarado-Ortega [jalvarado@yahoo.com.mx], Instituto Geologia Cd universitaria, Circuito de la investigacion, Del. coyoacan, C.P. 04510, Ciudad de México, México; Lionel Cavin [lionel.cavin@ville-ge.ch], Section of Earth Sciences, Muséum d’Histoire naturelle de la Ville de Genèeve, CP 6434, 1211 Genève 6, Switzerland; Steven W. Salisbury [s.salisbury@uq.edu.au], School of Biological Sciences, The University of Queensland, Brisbane St Lucia, Queensland, 4072, Australia; Anne Kemp [annerkemp@gmail.com], 9 Hampton Grove, Norwood, Adelaide, South Australia 5067, Australia. #Also affiliated with: School of Molecular and Life Sciences, Curtin University, Kent Street, Bentley, WA 6102, Australia.

Morphological variation in sexually matured Sarotherodon galilaeus was assessed from commercial fishermen operating Iken brushpark – fish aggregating device in Ogun State coastal estuary, Nigeria. Fifteen morphometric features and nine meristic characters were analysed using both univariate and multivariate analyses between the sexes of the population. Univariate analysis showed higher mean values in most of the morphometric and meristic counts of the female population than the males, but significant differences (p<0.05) were recorded in total length, standard length, head length, pectoral ray and gill raker of the first arch. Two and four Principal components were extracted for morphometric and meristic characters with 78.702% and 63.428% total variances respectively. Sexual differences occurred in morphometric characters such as, eye diameter, body weight, head width, length of dorsal base and length of pectoral fin while meristic counts showed overlapping in spinous dorsal fin rays, pectoral fin rays, scales along lateral line, scales above lateral line and gill rakers on the first arch. Canonical Discriminant function revealed the heterogeneity of total length, pectoral fin rays and gill rakers on the first arch in both sexes and these features could be used for the identification of the fish. This study revealed that multivariate statistical tools are effective means of analysing data for proper taxonomy, conservation and management of fish stocks.Keywords: Morphological traits, Multivariate analysis, Sarotherodon galilaeus, brushpark, meristic characters

ABSTRACT The book “Peixes da planície de inundação do alto rio Paraná e áreas adjacentes” represents the most cohesive data compilation for the rio Paraná floodplain. However, considering the dynamicity of the taxonomy of freshwater fishes, several new records and taxonomic changes occurred along the past years. Therefore, the results of that publication were revisited, providing an update of the species list, their taxonomic status, records and geographic distribution, and also new keys for genera and species. The species included were those recorded in the rio Paraná basin, from the mouth of the rio Paranapanema to the Itaipu Reservoir, following the general methodology presented in the book. A total of 10 orders, 41 families, 126 genera, and 211 species were registered, with an increase of one order, six families, 14 genera, and 29 species when compared to the book. Additionally, four new genera recently described, five synonymization proposals, 14 new identifications, four new combinations, 12 new species recently described, 34 new records, and nine misidentified species were recorded. These results are associated with the redirection of human and financial resources to that area, which enabled monitoring and intensive exploration of its watercourses; as well as training of taxonomists, and new taxonomic resolutions.

Half-fin anchovy (Setipinna tenuifilis) is one of the most important economic fishes around the world. In the present study, we determined the complete mitochondrial DNA sequence and organization of S. tenuifilis. The entire mitochondrial genome is a circular-molecule of 16,215 bp in length, which encodes 37 genes in all. These genes comprise 13 protein-coding genes (ATP6 and 8, COI–III, Cytb, ND1-6, and 4L), 22 transfer RNA genes (tRNAs), and two ribosomal RNA genes (12S and 16S rRNAs), with gene arrangement and content basically identical to those of other species of Engraulidae. The result of phylogenetic analysis strongly supported that S. tenuifilis was first clustered together with Setipinna melanochir and formed a monophyly in the genus Coilia, and then they constituted a sister-group relationship with two genus Engraulis, and Stolephorus. It concluded that the S. tenuifilis should be classified into the genus Setipinna. The present study also revealed the phylogenetic relationship of this genus at molecular levels. The complete mitochondrial genome sequence of S. tenuifilis can provide basic information for the studies on molecular taxonomy and phylogeny of teleost fishes.

フグ目魚類の多様性と系統,そして分類(第12回日本動物分類学会奨励賞受賞記念論文)

ABSTRACT Studies on the diversity, taxonomy, phylogeny, and biogeography of Neotropical Fishes have thrived over the twenty years that have elapsed since the first symposium on their phylogeny and classification in Porto Alegre, Brazil. Here, we review recent advances in the study of Neotropical fishes and assess the known diversity of freshwater species in that region. 6,255 valid freshwater species have been discovered in the Neotropics so far, and we estimate that over 9,000 species will be known when the inventory is complete. We also summarize the events of the second Symposium on Phylogeny and Classification of Neotropical Fishes that took place last year in Londrina, Brazil. Along with invited talks on the biodiversity of all major groups of Neotropical fishes, a series of presentations on the development of fish collections, and numerous contributed talks, the meeting included a special session to honor Dr. Richard Vari, who was one of the most prolific and beloved members of our community.

Abstract. Taxonomy of extinct fishes is mostly based on the shapes of their bodies, teeth and skeletons and sometimes the coverage of the body. Analysis of modern fishes shows that sometimes even single-scale morphology can also be used as a taxonomic tool. In spite of the fact that variation in scales character in one species can be broad, some specific features distinguish species of the same genus. Analysis of the fossilized scales of fishes found in the Late Triassic deposits of Krasiejow (SW Poland) shows that the microstructure of the external surface of scales can also be considered as a taxonomic tool in the fossil record. Description of the ornamentation pattern of several scales of fishes from the same group shows diversity of the sculpture, which might be assigned to variation in morphology between several genera or species. Among the scales from Krasiejow there occur the oldest known ctenoid scales (sensu stricto) belonging to acanthopterygians.

Understanding the pathways and impacts of non-native species is important for helping prevent new introductions and invasions. This is frequently challenging in regions where human activities continue to promote new introductions, such as in Brazil, where aquaculture and sport fishing are mainly dependent on non-native fishes. Here, the non-native fish diversity of the Paranapanema River basin of the Upper Parana River ecoregion, Brazil, was quantified fully for the first time. This river has been subject to considerable alteration through hydroelectric dam construction and concomitant development of aquaculture and sport fishing. Through compilation of a non-native fish inventory by literature review, with complementary records from recent field studies, analyses were completed on the timings of introduction, and the taxonomy, origin and introduction vectors of the non-native fishes. A total of 47 non-native fishes are now present across the basin. Of these, 24 invaded from the Lower Parana River following construction of Itaipu Dam that connected previously unconnected fish assemblages. Activities including fish stocking, aquaculture and sport angling continue to result in new introductions. Discounting Itaipu invasions, the introduction rate between 1950 and 2014 was approximately one new introduction every 3 years. Introduced fish were mainly of the Cichlidae and Characidae families; most species were from other South American ecoregions, but fishes of African, Asian, North American and Central American origin were also present. These introductions have substantially modified the river’s fish fauna; when coupled with altered lentic conditions caused by impoundment, this suggests that the river’s native fishes are increasingly threatened.

Taxonomy of the live-bearing fish of the genus Ilyodon Eigenmann, 1907 (Goodeidae), in Mexico, is controversial, with morphology and mitochondrial genetic analyses in disagreement about the number of valid species. The present study accumulated a comprehensive DNA sequences dataset of 98 individuals of all Ilyodon species and mitochondrial and nuclear loci to reconstruct the evolutionary history of the genus. Phylogenetic inference produced five clades, one with two sub-clades, and one clade including three recognized species. Genetic distances in mitochondrial genes (cytb: 0.5%–2.1%; coxI: 0.5%–1.1% and d-loop: 2.3%–10.2%) were relatively high among main clades, while, as expected, nuclear genes showed low variation (0.0%–0.2%), with geographic concordance and few shared haplotypes among river basins. High genetic structure was observed among clades and within basins. Our genetic analyses, applying the priority principle, suggest the recognition only of Ilyodon whitei and Ilyodon furcidens, with I. cortesae relegated to an invalid species, the populations of which belong to I. whitei.