Molecular phylogeny of basal gobioid fishes: Rhyacichthyidae, Odontobutidae, Xenisthmidae, Eleotridae (Teleostei: Perciformes: Gobioidei)

Morphological character analyses indicate that Rhyacichthyidae, Odontobutidae, Eleotridae, and Xenisthmidae are the basal families within the perciform suborder Gobioidei. This study uses DNA sequence data to infer the relationships of genera within these families, as well as determine the placement of more derived gobioids (family Gobiidae) and the identity of the outgroup to Gobioidei. Complete sequences of the mitochondrial ND1, ND2, COI, and cyt b genes (4397 base pairs) are analyzed for representatives of 27 gobioid genera and a variety of perciform and scorpaeniform outgroup candidates; the phylogeny is rooted with a beryciform as a distal outgroup. The single most parsimonious tree that results indicates that, of the outgroups sampled, the perciform family Apogonidae is most closely related to Gobioidei. Gobioidei is monophyletic, and Rhyacichthys aspro is the most basal taxon. The remainder of Gobioidei is resolved into clades corresponding to the families Odontobutidae (plus Milyeringa) and Eleotridae+Xenisthmidae+Gobiidae. Within Eleotridae, the subfamily Butinae (minus Milyeringa) is paraphyletic with respect to Gobiidae, and Eleotrinae is paraphyletic with respect to Xenisthmidae. Other than these groupings, the primary disagreement with the current morphology-based classification is that the molecular data indicate that the troglodytic Milyeringa should be placed in Odontobutidae, not Butinae, although support for this placement is weak. The most basal lineage of Gobioidei is known from the freshwaters of the Indo-Pacific, with marine-dwelling lineages arising several times independently in the group. The phylogeny also indicates that different gobioid lineages are distributed in Asia, Africa, Madagascar and the Neotropics. Five sister pairs of basal gobioid species inhabit Atlantic and Pacific drainages of Panama, with widely varying divergences.     

Innervation of the lateral line system in Rhyacichthys aspro: the origin of superficial neuromast rows in gobioids (Perciformes: Rhyacichthyidae)

The lateral line system and its innervation were examined in the most primitive gobioid taxon, Rhyacichthys aspro (Rhyacichthyidae). The infraorbital canal was present, whereas superficial neuromast rows a and c, typically present on the cheek of gobioids, were absent. Because the infraorbital canal (absent in other gobioids) and the two rows were commonly innervated by the buccal ramus, the latter were categorized as replaced rows from canal neuromasts. On an innervation basis, rows b and d on the cheek were considered to comprise superficial neuromasts only in all gobioids. The trunk lateral line system comprised canal and superficial neuromasts, the former being included in the lateral line scales (each bearing 1–7 neuromasts arranged longitudinally along the direction of a groove). Absence of bony roofs in the lateral line system was proposed as a synapomorphy of Gobioidei, and a progressive neotenic shift in the lateral line system of the suborder discussed.     

Encephalization in Gobioidei (Teleostei)

We have measured the brain and body weight and determined the encephalization index for 180 species of fishes belonging to six families of the suborder Gobioidei. Within the Teleostei, these fishes exhibit a remarkably broad range in the values of their encephalization indices, but most values are in the low to middle range. Within the Gobioidei there is relatively little difference in the degree of encephalization among the different families and subfamilies except the Kraemeriidae and Amblyopinae which have low encephalization indices and the Oxudercinae (including Periophthalmus) and Rhyacichthyidae which are highly encephalized. We have shown that the form of the body has an effect on the degree of encephalization. Elongate fishes have low values, probably because of the excessive mass of their body skeleton which raises the body weight relative to the brain size. The environment in which the fishes live is correlated, in general, with their relative brain size. The values of the encephalization index arranged from low to high by habitat are as follows: muddwelling fishes, freshwater fishes, brackishwater fishes, burrowing marine fishes, freeliving marine fishes, torrent fishes and amphibious fishes. The low values of the Amblyopinae and Kraemeriidae can be explained in terms of their being both mud-dwelling and elongate.     

Complete mitochondrial genome of Oxuderces dentatus (Perciformes, Gobioidei)

The complete mitochondrial genome (mitogenome) of Oxuderces dentatus was determined first. The genome was 17,116?bp in length and consisted of 13 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA genes, and 2 main non-coding regions [the control region (CR) and the origin of the light strand replication], the gene composition and order of which was similar to most other vertebrates. The overall base composition of the heavy strand was T 27.9%, C 26.8%, A 30.2%, and G 15.1%, with a slight A+T bias of 58.1%. In addition to the discrete and conserved sequence blocks, unusual long tandem repeat unit (three 150-bp tandem repeat units and an incomplete copy of 146?bp) was also detected within CR. This mitogenome sequence data would play an important role in population genetics and phylogenetic analysis of the Gobioidei.     

Complete mitochondrial genome of Trypauchen vagina (Perciformes, Gobioidei)

The complete mitochondrial genome of Trypauchen vagina was determined first. The genome is 16,686 bp in length and consists of 13 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA genes, and 2 main non-coding regions [the control region (CR) and the origin of the light strand replication], the gene composition and order of which was similar to most other vertebrates. The overall base composition of T. vagina is T 27.6%, C 27.6%, A 29.5%, and G 15.3%, with a slight A+T bias of 57.1%. In addition to the discrete and conserved sequence blocks, an incomplete tandem repeat unit is detected within the CR. This mitogenome sequence data would play an important role in population genetics and phylogenetic analysis of the Gobioidei.     

Larval development of the Amur sleeper Perccottus glenii (Perciformes, Gobioidei, Odontobutidae) and the origin of fish of the suborder Gobioidei

The external morphology and development of skeletal elements is investigated in larvae and fry of one of the most generalized representatives of the suborder Gobioidei—the Amur sleeper Perccottus glenii. It is characterized by an indirect type of development accompanied by the expressed metamorphosis, according to Balon’s classification (1985). Fry of P. glenii are capable of an active mode of life and exogenous feeding almost immediately after hatching which favors a wide distribution of this species. Morphogenesis of previously revealed diagnostic characters of Gobioidei is investigated. New apomorphies are found also indicating to a high separation level of P. glenii from representatives of other suborders of Perciformes. At the same time, it is found that some developmental traits of P. glenii are characteristic of generalized Perciforems. Some advanced characters acquired in parallel with representatives from the group of suborders Blennioidei s. l. also indirectly indicate that P. glenii and, generally, Gobioidei belong to Perciformes. Analysis of special traits of development of the skeleton of P. glenii supports the ideas of Regan (1911) on the origin of Gobioidei from generalized Percoidei. With consideration of advanced characters, general for Gobioidei and the suborders Trachinoidei, Notothenioidei, Zoarcoidei, and Blennioidei of the group Blennioidei s. l., it is assumed that Gobioidei and Blennioidei s. l. stem from the same group or from the related groups of Percoidei.     

The innervation of head neuromast rows in eleotridine gobies (Teleostei: Gobioidei)

The innervation of free neuromast (sensory papillae) rows is described from Sihler wholemount preparations of four species of eleotridine gobies, one ( Perccottus glenii ) representing the 'longitudinal' type of neuromast arrangement, the others ( Butis buits, Bostrychus urophthalmus, B. marmoratus ) the 'transverse' arrangement. In the latter, the characteristic transverse cheek rows (1–7) are innervated from the infraorbital trunk of the anterior lateral-line nerve. Longitudinal cheek rows b and d , and the three opercular rows, ot, os and oi , common to all species, are innervated by rami of the hyomandibular trunk of the same nerve. Two neuromast groupings are shown to have a mixed nerve supply. For the median preorbital snout rows, there is innervation from the infraorbital ( s ³ and r ) as well as the supraorbital ( s ¹ and s ²) trunks of the anterior lateral line nerve. The anterior dorsal rows are supplied both by the posterior lateral-line supratemporal ramus (rows g and m ) and the anterior lateral-line supraorbital trunk (rows o and n ). The neuromast rows, under the designations of Sanzo, are tabulated according to innervation and their putative origin in the phyletic replacement of a complete head canal system seen in more generalized percomorph fishes.     

A redescription of Pomatoschistm norvegicus (Collett, 1903) (Teleostei: Gobioidei) based on syntype material

A deeper water species of the Mediterranean-Atlantic gobiid genus Pomatoschistus, P. norvegicus (Collett, 1903), is redescribed from syntype material, including details of the lateral-line system and a summary of geographical distribution. The systematic status of P. norvegicus is briefly discussed with reference to the other nominal species, P. minutus (Pallas) and P. lozanoi (De Buen), of the 'P. minutus' complex.     

New genus of Ptereleotrinae (Gobioidei) from the South China Sea

A new genus and species Zagadkogobius ourlazon gen. et sp. nov. characterized by an unusual (for the subfamily Ptereleotrinae) combination of characters is described. A single specimen was collected at a depth of 73 m in the southwestern South China Sea to the south of the Anambas Islands. Based on the combination of characters, the new genus is most similar to the genus Nemateleotris. However, the species of the latter genus are associated exclusively with coral reefs. A key to the genera of the subfamily Ptereleotrinae is presented.     

First record of the paedomorphic fish Schindleria (Gobioidei, Schindleriidae) from the Red Sea

A male specimen of the paedomorphic fish Schindleria sp. was collected by plankton net, in February 2005, from a reef lagoon from Hurghada on the Egyptian coast of the northern Red Sea. This is the first record of the Schindleriidae in the Red Sea.     

Gobies (Gobioidei) of soft bottoms from Nha Trang and Van Phong bays (South China Sea,Vietnam)

Gobioid fishes collected in Nha Trang and Van Phong bays (Vietnam) represented by 44 species, including 30 species continuously associated with soft bottoms in the open parts of the bays with normal marine conditions are reviewed. A new species, Navigobius khanhoa sp. n., is described. This species differs from other species of the genus in much higher number of rays in the second dorsal fin (26), smaller size of the mouth, teeth on the jaws arranged in a single row, and other characters. Four species from the genera Acentrogobius, Eviota, Favonigobius, and Gnatholepis have not been identified to the species, and, most likely, some of them are new for science. Nine species are recorded in the fauna of Vietnam for the first time: Aulopareia unicolor, Bathygobius hongkongensis, Egglestonichthys bombylios, Glossogobius circumspectus, Oplopomops diacanthus, Oxyurichthys auchenolepis, Tomiyamichthys ex gr. russus, Tryssogobius porosus, and Valenciennea immaculata. An occurrence of Glossogobius olivaceus in the fauna of Vietnam is confirmed. Three species, G. olivaceus, Oligolepis acutipennis, and Periophthalmus kalolo, are recorded in the Cai River delta for the first time. A new synonymy is established: Eviota gurjanovae (Prokofiev, 2007) = E. prasina (Klunzinger, 1871). The current state of knowledge of Gobiidae fauna of Vietnam is discussed, and the updating of the species composition of Gobiodontini of Nha Trang Bay is presented in addition to the species list published earlier (Prokofiev, 2007).     

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.     

Asterropteryx atripes, a new gobiid fish from the Western Pacific Ocean (Perciformes: Gobioidei)

 A new gobiid fish, Asterropteryx atripes, is described on the basis of eight specimens from Iriomote-jima Island, Ryukyu Islands, and El Nido, Philippines. It differs from its congeners by having the following combination of characters: 3rd spine of first dorsal fin long, filamentous, distal tip usually over end of 2nd dorsal fin base when appressed in both sexes; pelvic fins almost separated, innermost (=5th) segmented rays connected by rudimentary low membrane between bases, and no frenum; 4–7 short spines on posterior margin of preopercle (the uppermost spine usually just behind the cephalic sensory canal pore N); eye large, 32.3–35.8% of head length; enlarged haemal arches on 1st two caudal vertebrae; a distinct black band from posterior margin of eye to caudal fin base (indistinct in dark-phase individuals); black pelvic fin (vivid in dark-phase individuals); numerous minute bright blue spots on head and body in life; no distinct dark spots on head and body; iris entirely reddish-brown or dusky (bright white ventrally in pale-phase individuals) when alive or fresh, and entirely black in preservation, without white transverse bar on middorsal surface; hovering habit. The new species appears to be most closely related with the other only known hovering species, A. striata; the latter is readily distinguished from the former in having no long, filamentous dorsal spine; semitranslucent pelvic fin; and a series of small black spots along dorsal fin base and dorsal edge of caudal peduncle. Asterropteryx contains two distinct groups, and the monophyly of the genus is open to question. Received: March 19, 2000 / Revised: February 25, 2002 / Accepted: April 25, 2002     

Reproductive effort and efficiency in the female common goby, Pomatoschistus microps (Krøyer) (Teleostei: Gobioidei)

Reproductive effort and efficiency are terms which together help to describe the reproductive investment of spawning fish. In this paper they are applied to a small and abundant inshore fish, the common goby, Pomatoschistus microps (Kroyer), based on data collected from the wild, and by modelling likely breeding patterns. Wet calorimetry was used to determine the energy content offish tissue, and this allowed reproductive effort to be expressed as both an energy and a weight ratio of gonad to somatic body. The gonadosomatic index (GSI) calculated as an energy ratio was greater than that calculated as a dry weight ratio. For ripe females the GSI (dry weight) at the onset of breeding was 67.5%. Theoretical and observed values of the maximum number of egg batches laid by a single female during a 16-week breeding season are 9-10, and this corresponds to a total caloric investment of almost 12 kJ. Estimates of the reproductive efficiency, using the dietary energy content during the breeding season, range from 28.2% to a maximum of 44.0%. These values are among the highest calculated for a fish species, and are in keeping with the long and intensive breeding strategy observed in the wild population.     

Isozyme genetics and the phytogeny of Italian freshwater gobies (Teleostei: Gobioidei)

Although predominantly a marine group in the Atlantic/Mediterranean fish fauna, three species of exclusively freshwater gobies (Teleostei: Gobiidae) occur in Italy. These are Padogobius marltmsii of north Italy and parts of Croatia, P. nigricans from the Tyrrhenian catchment area of Tuscany and Lazio, and Knipowitschia punctatissima from north-eastern Italy. Using horizontal starch-gel electrophoresis, isozyme polymorphism in 12 enzymes encoded at 18 loci was investigated in these species and related euryhaline forms. Genetic distance, and morphological cladistic analysis, indicates that the Italian freshwater gobies do not form a monophyletic group, with the Padogobius species well separated from other taxa, and K. punctalissima closest to its morphological congener, the lagoonal K. panizzae . No close correlation was found between genetic variation and environmental heterogeneity.     

Additions to the Gobioidei Fauna of Nha Trang and Phan Thiet Bays (South China Sea,Vietnam)

Journal of Ichthyology - Information is provided on new specimens of the recently described Amblyeleotris memnonia species (Gobiidae), previously known only by its holotype. The absence of...     

Juvenile morphology and occurrence patterns of three Butis species (Gobioidei: Eleotridae) in a mangrove estuary, southern Thailand

Juveniles of three eleotrid Butis species (B. butis, B. humeralis, and B. koilomatodon) are described; their occurrence patterns were examined in Sikao Creek, a mangrove estuary located in southern Thailand. Juveniles of each species were distinguished by the following characters: B. butis with no bands on body and pale pelvic fins; B. humeralis with no bands on body and densely pigmented pelvic fins; and B. koilomatodon with 5–6 regular bands on body and a fleshy process (preorbital knob) on the snout. Although B. butis shared the aforementioned characters with B. amboinensis found in the same estuary, the former was distinguished from the latter by having a greater number of pectoral fin rays (18–21 vs. 17) and a deeper caudal peduncle. Distribution patterns of the three Butis species in Sikao Creek were distinguishable from each other. Smaller B. butis [mean ± SD = 22.7 ± 16.9 mm in standard length (SL), n = 32] occurred in the upper reach of the estuary, while larger specimens (52.4 ± 26.2 mm SL, n = 18 and 51.5 ± 29.7 mm SL, n = 10, respectively) were found in the middle and lower reaches and none in the marine area. In B. humeralis and B. koilomatodon, only juveniles were caught except for one adult specimen each. Juveniles (8.9–16.5 mm SL, n = 79) of B. humeralis occurred in the upper and middle reaches and the marine area. B. koilomatodon juveniles (9.9–13.7 mm SL, n = 30) were distributed in all areas from the lower to upper reaches.     

Gobies are deeply divided: phylogenetic evidence from nuclear DNA (Teleostei: Gobioidei: Gobiidae)

Gobies (Gobiidae sensu Gill & Mooi, 2012 Gill, A. and Mooi, R. 2012. Thalasseleotrididae, new family of marine gobioid fishes from New Zealand and temperate Australia, with a revised definition of its sister taxon, the Gobiidae (Teleostei: Acanthomorpha). Zootaxa, 3266: 41–52.  [Google Scholar]) are one of the most diverse families of vertebrates, and comprise over 1700 species of marine, brackish and freshwater fishes. Phylogenetic studies based on morphological characters and mtDNA have suggested that goby diversity is asymmetrically split between a speciose clade of predominantly marine species, and a less rich, but ecologically diverse, clade comprising predominantly freshwater and brackish species. This study is the first to explore this deep divide in gobies and their relationships at the family level using phylogenetic data from nuclear genes (RAG1, rhodopsin). Our results confirm the split within the Gobiidae, and agree with prior molecular studies on the inclusion of the following taxa within the two goby clades: (i) the more diverse of the two clades of gobies (the ‘Gobiidae’ sensu stricto of Thacker 2009 Thacker, C. E. 2009. Phylogeny of Gobioidei and placement within Acanthomorpha, with a new classification and investigation of diversification and character evolution. Copeia, 1: 93–104. doi:10.1643/CI-08-004[Crossref], [Web of Science ®] , [Google Scholar]) comprises the gobiines, microdesmines, ptereleotrines and kraemeriines; (ii) the less diverse of the two gobiid clades (‘Gobionellidae’ sensu Thacker 2009 Thacker, C. E. 2009. Phylogeny of Gobioidei and placement within Acanthomorpha, with a new classification and investigation of diversification and character evolution. Copeia, 1: 93–104. doi:10.1643/CI-08-004[Crossref], [Web of Science ®] , [Google Scholar]) includes the gobionellines, oxudercines, amblyopines, sicydiines, as well as the European sand gobies. Some relationships within the two major gobiid clades remain unclear. Specifically, there remains confusion regarding the monophyly and interrelationships between the northern Pacific gobionellines, the Mugilogobius group gobionellines, and the European sand gobies. Additionally, within Thacker's (2009 Thacker, C. E. 2009. Phylogeny of Gobioidei and placement within Acanthomorpha, with a new classification and investigation of diversification and character evolution. Copeia, 1: 93–104. doi:10.1643/CI-08-004[Crossref], [Web of Science ®] , [Google Scholar]) Gobiidae sensu stricto, there are several well-supported groups (e.g. the wormfishes and dartfishes, the Coral Gobies, the Gobiosomatini), yet relationships among these groups are still poorly resolved despite the use of data from two conserved nuclear genes. Future phylogenetic analyses of gobies will benefit greatly from taxon sampling that includes groups that have been historically under-represented in molecular studies (e.g. European sand gobies, northern Pacific gobionellines, African species), as well as deeper genetic sampling including large numbers of independent loci from throughout the genome (i.e. a phylogenomic approach).     

Molecular phylogeny of gobioid fishes (Perciformes: Gobioidei) based on mitochondrial 12S rRNA sequences

The molecular phylogeny of the gobioid fishes, comprising 33 genera and 43 valid species, was examined by use of complete mitochondrial 12S rRNA and tRNA(VAL)genes. Both parsimony and neighbor-joining analyses revealed comparable results and are generally congruent with those of morphological studies. The Odontobutis, which was always placed at the base of the phylogenetic trees, can be treated as a sister group of all other nonrhyacichthyid gobioids. Within eleotrid fishes, the monophyly of the Eleotrinae is strongly supported by molecular data. The Butinae is closer to fishes with five branchiostegal rays and should be treated as a sister group of the latter. The group with five branchiostegal rays, except for sicydiines, can be divided into two groups according to their epural counts. Fish with one epural, the Gobiinae of Pezold plus Microdesmidae, form a monophyletic group which is sister to those with two epurals, the Oxudercinae and Gobionellinae of Pezold. However, Sicydiinae, which have one epural, are closer to the Oxudercinae and Gobionellinae rather than to the Gobiinae. Since progressive reduction in epural number has been observed along this lineage, the sicydiines should be treated as a derived group within the groups with two epurals.