Position of neck banded blenny Leptostichaeus pumilus (Perciformes: Zoarcoidei) in the system of the suborder Zoarcoidei as inferred from molecular genetic data

Molecular genetic study of genetic variations within COI, cytochrome b, and 16S rRNA of mitochondrial DNA in neck banded blenny Leptostichaeus pumilus, which was earlier assigned to the family Stichaeidae, indicates that the species is most close to a group combining the families Zoarcidae, Neozoarcidae, and Anarhichadidae. Significant genetic differences between neck banded blenny and the family Stichaeidae correspond to the level of divergence between other families of the suborder Zoarcoidei (Zaproridae, Ptilichthyidae, Pholidae, Cryptacanthodidae, and Bathymasteridae).     

Relationships and position of wrymouths of the family cryptacanthodidae in the system of the suborder Zoarcoidei (Pisces,Perciformes)

To determine the taxonomic position of wrymouths of the family Cryptacanthodidae in the system of the suborder Zoarcoidei, a study on molecular genetics and comparative morphology of Cryptacanthodes bergi from Peter the Great Bay (Sea of Japan) is conducted. Based on molecular genetic analysis using the genes of nuclear and mitochondrial DNA, Cryptacanthodes bergi is substantially similar to the representatives of the superfamily Stichaeoidae. Thus, the opinion of Makushok on a phylogenetically distinct position of wrymouths in relation to snake blennies and related families is not supported. The anatomical features of skull structure support the data of molecular genetics. The directions and time of distribution of wrymouths in the northwest Atlantic through the channel in the area of the Isthmus of Panama in approximately the late Miocene are discussed.     

Position of the genus Azygopterus (Stichaeidae,Perciformes) in the system of the suborder Zoarcoidei as inferred from sequence variation of mitochondrial and nuclear genes

Analysis of sequence variation in the mitochondrial and nuclear genes in Azygopterus corallinus showed that this species was genetically close to the group uniting the representatives of the families Zoarcidae, Neozoarcidae, and Anarhichadidae. The considerable genetic differences between A. corallinus and the members of the family Stichaedae, to which it was assigned earlier, are consistent with the divergence estimates between the other families of the suborder Zoarcoidei (Zaproridae, Ptilichthyidae, Pholidae, Cryptacanthodidae, Bathymasteridae).     

Relationships and position of the taxa of the subfamily Xiphisterinae in the system of the suborder Zoarcoidei (Perciformes)

Analysis of the nucleotide sequences of mitochondrial and nuclear DNA genes was used to examine the relationships and position of the subfamily Xiphisterinae in the system of the suborder Zoarcoidei. This study showed the genetic heterogeneity of Xiphisterinae and the propriety of its division into two subfamilies: Xiphisterinae with the genera Xiphister and Phytichthys and Cebidichthyinae with the genera Cebidichthys, Dictyosoma, Esselenichthys, and Nivchia. The genetic differences between the two subfamilies were not less, but in some cases even greater than the differences between families within the suborder; therefore, they should be raised to the rank of a family, Xiphisteridae and Cebidichthyidae, and classified not within the superfamily Stichaeoidae but rather as independent taxa of the suborder Zoarcoidei.     

Osteology of the Graveldiver Scytalina cerdale (Perciformes: Zoarcoidei: Scytalinidae)

The Graveldiver, Scytalina cerdale, is a small, poorly known burrowing fish from the intertidal and subtidal zones of the west coast of North America, ranging from south‐central California to Alaska. This is the sole member of the family Scytalinidae, which is included in the Zoarcoidei. Although it was described over 120 years ago, it is rare in natural history collections and its anatomy is only imperfectly known. This article describes and illustrates the skeletal anatomy of S. cerdale based on newly prepared cleared and stained specimens. Many points of its anatomy are clarified or corrected (e.g., presence of the intercalars and ribs, in contrast to their reported absence) or described for the first time (e.g., structure of its gill‐arches). Previous hypotheses of its systematic placement within the Zoarcoidei are discussed. On the basis of preliminary comparisons, S. cerdale may have phylogenetic affinity with at least some members of the family Stichaeidae (e.g., Xiphister). However, further study is needed on the anatomy and inter‐relationships of the families of the Zoarcoidei before any conclusions can be made. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.     

New data elucidating the taxonomy and ecology of the Parabrotulidae (Pisces: Zoarcoidei)

One hundred and eighty-two new specimens of Parabrotula and 52 Leucobrotula are reported. Generic separation is confirmed. although premaxillary dentition no longer distinguishes the two. Two species of Parabrotula (one yet to be described) and one of Leucobrotula are strongly indicated from meristic data. Breeding biology is considered, with comment upon sexual dimorphism in size, size at maturity and possible breeding period. Parabrotulu plagiophthalmus Zugmayer, 1911 is shown to be a midwater non-migrant species (range 76@1500 m) with a temperature preference in the eastern North Atlantic of 9.0–5.0° C. Leucobrotulu udipatus Koefoed, 1952 exhibits a depth range of 61–1290 m and a temperature range of 9.0–4.2° C. Geographically it is evidently restricted to the North Atlantic and endemic to the eastern side. Most specimens were caught pelagically in the northwest African upwelling area in slope waters. Parabrotulaplagiophthalnius is distributed worldwide, although 89% came from the eastern North Atlantic.     

A new genus and species of prickleback (Perciformes: Stichaeidae) from Japan

A stichaeid fish, Xenolumpenus longipterus gen. et sp. nov., is described on the basis of 2 specimens (107.1–114.9 mm in standard length) collected from 167 to 300 m in the northern Sea of Japan off southern Hokkaido, Japan. Xenolumpenus is unique among all known genera of the subfamily Lumpeninae in having all pectoral, pelvic, and anal fin rays elongate and unbranched with fin membranes well-incised. Xenolumpenus longipterus can be further distinguished from all species of the subfamily in having the following combination of characters: dorsal fin XLVI–XLVIII; anal fin II, 28–29; pectoral fin 11; large black blotches on pectoral fin; and black ocellus on caudal fin.     

Morphology and ontogeny of multiple lateral‐line canals in the rock prickleback,Xiphister mucosus (Cottiformes: Zoarcoidei: Stichaeidae)

The structure and ontogeny of lateral‐line canals in the Rock Prickleback, Xiphister mucosus, were studied using cleared‐and‐stained specimens, and the distribution and morphology of neuromasts within lateral‐line canals were examined using histology. X. mucosus has seven cephalic canals in a pattern that, aside from four branches of the infraorbital canals, is similar to that of most teleostean fishes. Unlike most other teleosts, however, X. mucosus features multiple trunk lateral‐line canals. These include a short median posterior extension of the supratemporal canal and three paired, branching canals located on the dorsolateral, mediolateral, and ventrolateral surfaces. The ventrolateral canal (VLC) includes a loop across the ventral surface of the abdomen. All trunk canals, as well as the branches of the infraorbitals, are supported by small, dermal, ring‐like ossifications that develop independently from scales. Trunk canals develop asynchronously with the mediodorsal and dorsolateral canals (DLC) developing earliest, followed by the VLC, and, finally, by the mediolateral canal (MLC). Only the mediodorsal and DLC connect to the cephalic sensory canals. Fractal analysis shows that the complexity of the trunk lateral‐line canals stabilizes when all trunk canals develop and begin to branch. Histological sections show that neuromasts are present in all cephalic canals and in the DLC and MLC of the trunk. However, no neuromasts were identified in the VLC or its abdominal loop. The VLC cannot, therefore, directly function as a part of the mechanosensory system in X. mucosus. The evolution and functional role of multiple lateral‐line canals are discussed. J. Morphol. 276:1218–1229, 2015. © 2015 Wiley Periodicals, Inc.     

Phylogenetic relations in the family pholidae (Perciformes: Zoarcoidei) based on genetic and morphological data

Molecular-genetic study of Pholidae of the suborder Zoarcoidei was first performed. Analysis of variation of genes of COI, cytochrome b, and 16S rRNA of mitochondrial DNA indicates different phylogenetic isolation of the family taxa. The groundlessness of separating subgenera (or genera) Enedrias and Allopholis and the rightfulness of including them in the composition of the genus Pholis are shown. Genetic close relation of the genera Pholis and Rhodymenichthys and their differences from the genus Apodichthys are established. The obtained results agree with the data of Makushok (1958) who separated in the composition of the family two subfamilies—Pholinae (with genera Pholis and Rhodymenichthys) and Apodichthyinae (with the genera Apodichthys, Xererpes, and Ulvicola). A key to species, genera, and subfamilies of gunnels of the northern part of the Pacific Ocean is provided.     

Molecular identification of Pampus fishes (Perciformes, Stromateidae)

Concerning the nomenclature, most problems arise from the great confusion due to the morphological similarities in Pampus. Twenty-five individuals in Pampus were sampled from different localities about 2,000 km apart along the coast of China covering the Yellow Sea, the East China Sea and the South China Sea. The sequences of cytochrome c oxidase I (COI) and 16S rRNA (16S) genes of the mitogenomes were determined. Combined with the morphological characteristics, five Pampus species, P. minor, P. punctatissimus, P. chinensis, P. cinereus and Pampus sp., were identified. The genetic distance of intraspecies ranged from 0.000 to 0.004, while it varied from 0.012 to 0.133 for interspecies based on the 16S sequences. For COI sequence data analysis, the genetic distance of intraspecies ranged from 0.000 to 0.005, while it varied from 0.057 to 0.162 for interspecies. Phylogenetic trees showed that all Pampus fishes reciprocally constituted a monophyletic group with strong support. The sister-group relationships between P. minor and Pampus sp. and between P. chinensis and P. punctatissimus were revealed respectively. In the current GenBank data, P. minor is considered P. cinereus or P. argenteus by mistake. For the lack of a P. echinogaster specimen, we cannot decide on the name of Pampus sp. as P. argenteus or P. echinogaster.     

Phylogenetic relationships of the stromateoid fishes (Perciformes)

The phylogenetic relationships of all 16 genera (plus Psenes pellucidus) of the suborder Stromateoidei were estimated cladistically based on 43 osteological, myological, and external characters. Thirty equally parsimonious trees were obtained. Based on the strict consensus tree, Centrolophidae was nonmonophyletic, Psenopsis being placed as a sister group of a clade comprising Amarsipus, Ariomma, nomeids, Tetragonurus, and stromateids. Schedophilus formed a sister group relationship with Seriolella. The relationships among the Centrolophus, Hyperoglyphe, Icichthys, Tubbia, Schedophilus+Seriolella clade, and Psenopsis+Amarsipus+Ariomma+nomeids+Tetragonurus+stromateids clade were unresolved. Amarsipus, which is unique within the suborder in lacking a pharyngeal sac, was nested within the stromateoid clade, being a sister group of the clade including Ariomma, nomeids, Tetragonurus, and stromateids. The absence of a pharyngeal sac in Amarsipus was interpreted as a reversal, its presence in the Stromateoidei therefore being considered as a synapomorphy. Ariomma was placed as the sister group of a clade comprising nomeids, Tetragonurus, and stromateids. Monophyly of the Nomeidae and Stromateidae were supported by 2 and 11 synapomorphies, respectively.     

A morphological description of the brown shanny Stichaeus fuscus Miki et Maruyama, 1986 (Perciformes: Stichaeidae)

Findings of the brown shanny Stichaeus fuscus Miki et Maruyama, 1986 in waters of Russia are reported for the first time. The morphology of S. fuscus is studied in detail based on representative material; the taxonomic characters of this species are revised. A key to the species of the genus Stichaeus is given.     

Diversified chromosomal characteristics in Centropyge fishes (Pomacanthidae, Perciformes)

We studied karyotypes and other chromosomal markers such as C-banded heterochromatin and Ag-stained nucleolus organizer regions (Ag-NORs), in seven Centropyge fishes (Pomacanthidae, Perciformes). These results revealed diversified chromosomal characteristics in Centropyge species. Three species had 2n = 48 chromosomes, whereas four species had 2n = 52 chromosomes. Fundamental numbers showed a large variation from 48 to 82, particularly in the species with 2n = 52 chromosomes. In all the species, Ag-NORs were located in a single chromosome pair and C-bands were mainly distributed in the centromeric regions of most chromosomes, as commonly seen in teleostean fishes. However, these chromosomal markers showed species-specific variations and provided us with useful information that could help us in understanding chromosomal evolution. On the basis of these chromosomal characteristics, we infer the process of chromosomal evolution, which according to us involves an increase in chromosome number from 2n = 48 to 2n = 52 through centric fission or other mechanisms, and in fundamental number through pericentric inversion. In particular, karyotypic evolution involving the increase in chromosome number is an unusual event in the evolution of higher teleostean groups. Handling editor: K. Martens     

Systematics of Tanganyikan cichlid fishes (Teleostei: Perciformes)

The relationships among 53 genera of Tanganyikan cichlid fishes were analyzed based on internal and external morphological features. Comparison of the morphological cladistic tree with a previously proposed classification showed 5 of 12 tribes to be nonmonophyletic. Sixteen tribes were recognized, the changes in classification being that Trematocarini was treated as a junior synonym of Bathybatini; 5 new tribes were established for each of the following genera, Benthochromis, Boulengerochromis, Ctenochromis benthicola, Cyphotilapia, and Greenwoodochromis; Ctenochromis horei was transferred from Haplochromini to Tropheini; and Gnathochromis pfefferi was transferred from Limnochromini to Tropheini. The revised classification was supported by previously proposed molecular trees.     

Molecular phylogeny of the gobioid fishes (Teleostei: Perciformes: Gobioidei)

The phylogeny of groups within Gobioidei is examined with molecular sequence data. Gobioidei is a speciose, morphologically diverse group of teleost fishes, most of which are small, benthic, and marine. Efforts to hypothesize relationships among the gobioid groups have been hampered by the prevalence of reductive evolution among goby species; such reduction can make identification of informative morphological characters particularly difficult. Gobies have been variously grouped into two to nine families, several with included subfamilies, but most existing taxonomies are not phylogenetic and few cladistic hypotheses of relationships among goby groups have been advanced. In this study, representatives of eight of the nine gobioid familes (Eleotridae, Odontobutidae, Xenisthmidae, Gobiidae, Kraemeriidae, Schindleriidae, Microdesmidae, and Ptereleotridae), selected to sample broadly from the range of goby diversity, were examined. Complete sequence from the mitochondrial ND1, ND2, and COI genes (3573 bp) was used in a cladistic parsimony analysis to hypothesize relationships among the gobioid groups. A single most parsimonious topology was obtained, with decay indices indicating strong support for most nodes. Major phylogenetic conclusions include that Xenisthmidae is part of Eleotridae, and Eleotridae is paraphyletic with respect to a clade composed of Gobiidae, Microdesmidae, Ptereleotridae, Kraemeriidae, and Schindleriidae. Within this five-family clade, two clades are recovered. One includes Gobionellinae, which is paraphyletic with respect to Kraemeriidae, Sicydiinae, Oxudercinae, and Amblyopinae. The other contains Gobiinae, also paraphyletic, and including Microdesmidae, Ptereleotridae, and Schindleriidae. Previous morphological evidence for goby groupings is discussed; the phylogenetic hypothesis indicates that the morphological reduction observed in many goby species has been derived several times independently.     

Timeline of the evolution of eelpouts from the suborder Zoarcoidei (Perciformes) based on DNA variability

Based on the analysis of variability of mitochondrial and nuclear DNA and calibration of the molecular clock using the paleontological data, the divergence time of the eelpouts is assessed. The temporal frames of the evolution of the suborder Zoarcoidei are restricted to the Late Oligocene and the middle of the Late Miocene, within a diapason of approximately 12 Ma. The families Bathymasteridae and Cebidichthyidae were the first to separate from the common ancestor, 14.7–22.5 and 13.1–19.1 Ma, respectively. The differentiation of other families occurred between the Middle and the Late Miocene approximately 10–15 Ma. The period from the Late Miocene to the Mid-Pliocene (3.6–7.8 Ma), most likely, was the time of the appearance and distribution of the present species of the suborder. Assessment of the DNA divergence rate in the eelpouts conducted in this study is in accordance with known evolutionary scenarios and with key steps of geological development of the World Ocean.     

Phylogeny and biogeography of cichlid fishes (Teleostei: Perciformes: Cichlidae)

Family level molecular phylogenetic analyses of cichlid fishes have generally suffered from a limited number of characters and/or poor taxonomic sampling across one or more major geographic assemblage, and therefore have not provided a robust test of early intrafamilial diversification. Herein we use both nuclear and mitochondrial nucleotide characters and direct optimization to reconstruct a phylogeny for cichlid fishes. Representatives of major cichlid lineages across all geographic assemblages are included, as well as nearly twice the number of characters as any prior family‐level study. In a strict consensus of 81 equally most‐parsimonious hypotheses, based on the simultaneous analysis of 2222 aligned nucleotide characters from two mitochondrial and two nuclear genes, four major subfamilial lineages are recovered with strong support. Etroplinae, endemic to Madagascar (Paretroplus) and southern Asia (Etroplus), is recovered as the sister taxon to the remainder of Cichlidae. Although the South Asian cichlids are monophyletic, the Malagasy plus South Asian lineages are not. The remaining Malagasy lineage, Ptychochrominae, is monophyletic and is recovered as the sister group to a clade comprising the African and Neotropical cichlids. The African (Pseudocrenilabrinae) and Neotropical (Cichlinae) lineages are each monophyletic in this reconstruction. The use of multiple molecular markers, from both mitochondrial and nuclear genes, results in a phylogeny that in general exhibits strong support, notably for early diversification events within Cichlidae. Results further indicate that Labroidei is not monophyletic, and that the sister group to Cichlidae may comprise a large and diverse assemblage of percomorph lineages. This hypothesis may at least partly explain why morphological studies that have attempted to place Cichlidae within Percomorpha, or that have tested cichlid monophyly using only “labroid” lineages, have met with only limited success. © The Willi Hennig Society 2004.