The osteology of <Emphasis Type="Italic">Bathysphyraenops symplex</Emphasis> and the diagnosis of the Howellidae (Perciformes: Percoidei) family

The osteology is described of Bathysphyraenops simplex, and its close relationship is demonstrated with genera Howella and Pseudohowella. These three genera should be classified into separate family Howellidae characterized by the specific structure of the bones of the infraorbital series, the absence of the hyomandibular process of metapterygoideum, and the reduction of the anterior plate of hyomandibulare, the absence of contact of pterygiophores of the 1st and 2nd dorsal fins, presence in front of the second dorsal fin of a free pterygiophore having no distal element, 16 caudal vertebrae, the characteristic structure of scales, and some other characters. The osteological distinctions of Bathysphyraemops simplex from Howella sherborni found for the first time are small and the author believes that some of them may make a case of interspecies variation within these genera. The revised diagnosis of the family Howellidae is presented. The status of the fossil genera Synagropoides and Cottopsis is discussed. They may become representatives of this family.     

Review of the <Emphasis Type="Italic">Chromis xanthura</Emphasis> species group (Perciformes: Pomacentridae), with description of a new species

A taxonomic review of the Chromis xanthura species group, defined here as having 13 dorsal-fin spines, three upper and three lower procurrent caudal-fin rays, two black bands at the preopercular and opercular margins, and a yellow caudal fin when juvenile, resulted in the recognition of three species, Chromis xanthura (Bleeker 1854), Chromis opercularis (Günther 1867), and Chromis anadema sp. nov. Chromis xanthura and C. opercularis, the Pacific and Indian Ocean paired sister species, respectively, are redescribed, with confirmation of two color types of C. xanthura (having a white or black caudal peduncle and fin) as a single species on the basis of morphological and molecular analyses. Chromis anadema sp. nov., described from the oceanic islands of the Pacific Ocean on the basis of 21 specimens, is characterized by having 28–33 gill rakers; longest dorsal-fin soft ray length 20.0–24.7% of standard length (SL); first anal-fin spine length 5.0–6.1% of SL; caudal-fin length 33.4–43.8% of SL; posterior tips of caudal-fin lobes not filamentous in adults; broad black bands along preopercular and opercular margins, sum width of two bands 28.9–38.7% of head length; distal half of soft-rayed portion of dorsal fin transparent in adults; triangular black blotches at upper and lower caudal-fin base in adults; caudal peduncle and fin bluish black in adults; and body grayish, and all fins (except for pectoral fin) bright yellow in juveniles.     

Morphometric Differences between Two Smelt Species, <Emphasis Type="Italic">Hypomesus japonicus</Emphasis> (Brevoort, 1856) and <Emphasis Type="Italic">H. nipponensis</Emphasis> (McAllister, 1963) (Pisces: Osmeridae) from The Northwestern Part of the Sea of Japan

Two smelt species that inhabit the northwest of the Sea of Japan, Hypomesus japonicus and H. nipponensis (family Osmeridae), which are both currently referred to as Japanese smelt, have been studied in order to clarify the taxonomic value of morphometric characters. Variations between individuals of these species have been revealed using a multivariate analysis of their morphometric characters and indices. The results of the analysis show that H. japonicus is distinguished from H. nipponensis both by the previously known characters (the eye diameter is smaller and the vertical through the beginning of the dorsal fin is closer to the head than that through the beginning of the pelvic fins) and by a greater height of the dorsal and adipose fins in the former species as defined in the paper. Within the species H. japonicus, the individuals sampled from Olga Bay are most similar morphologically to those from the coastal waters off the village of Terney. In contrast, the individuals of this species from the coastal waters off Russky Island and from Olga Bay manifest the greatest differences.     

New species of eel cods <Emphasis Type="Italic">Muraenolepis pacifica</Emphasis> sp. nova (Muraenolepididae) from the ridge of hercules (Pacific-Antarctic Ridge)

The new species of moray cod Muraenolepis pacifica sp. nova from the Pacific ocean, i.e., the Hercules and Umanov banks (Pacific-Antarctic Rise) from the depths of 200–500 m is described. The new species closely resembles M. orangiensis, but it reliably differs from the latter by the shorter caudal part of the body, more caudal position of the insertions of dorsal and pectoral fins, longer upper jaw, and other proportions of the body. The new data about holotype M. orangiensis obtained in its X-ray study are given.     

Redescription of <Emphasis Type="Italic">Lagocephalus cheesemanii</Emphasis> (Clarke 1897), a senior synonym of <Emphasis Type="Italic">Lagocephalus gloveri</Emphasis> Abe and Tabeta 1983, based on morphological and genetic comparisons (Actinopterygii: Tetraodontiformes: Tetraodontidae)

Lagocephalus gloveri Abe and Tabeta 1983 is shown to be a junior synonym of Tetrodon cheesemanii Clarke 1897 based on examination of morphological characters and DNA analysis of specimens collected from the western North Pacific, Australia and New Zealand. Lagocephalus cheesemanii is distinguished from other species of Lagocephalus by the following combination of characters: spinules on the back in a rhomboidal patch extending from the region between the nasal organ to the posterior part of the pectoral fin; caudal fin double emarginate with middle rays posteriorly produced; dorsal-fin rays 11–15; anal-fin rays 11–14; pectoral-fin rays 15–18; vertebrae 8+11=19; dorsal half of the body dark brown to brownish black; caudal fin dark brown to black with dorsal and ventral white tips. A neotype of L. cheesemanii is designated.     

A redescription and relationships of the congrid eel <Emphasis Type="Italic">Pavelichthys daniltshenkoi</Emphasis> (Anguilliformes: Congridae) from the lower Oligocene of Northern Caucasus

This study reanalyzed the morphology and discussed the relationships of a unique fossil conger Pavelichthys daniltshenkoi from the lower Oligocene of the Northern Caucasus. It belongs to the family Congridae by the presence of fused frontalia and the hyomandibulare inclined forward but differs from all representatives of the family by a significantly protruding lower jaw in combination with a large horizontal mouth. Pavelichthys is characterized by nonsegmented rays of the dorsal and anal fins, deep non-tapering caudal part of the body, well-developed pectoral and caudal fins, presence of the lateral ethmoidal process, supraoccipitale, and leaflike broadened parapophyses on the middle and posterior body vertebrae, about 90 trunk vertebrae, vertebral formula 9–～60–～150. By the combination of the traits, the Oligocene form should belong to the subfamily Bathymyrinae.     

<Emphasis Type="Italic">Micropleura huchzermeyeri</Emphasis> n. sp. (Camallanida: Dracunculoidea: Micropleuridae) from the Nile crocodile, <Emphasis Type="Italic">Crocodylus niloticus</Emphasis> Laurenti (Reptilia: Crocodylidae), in South Africa

Micropleura huchzermeyeri n. sp. (Camallanida: Dracunculoidea: Micropleuridae) is described from the peritoneal cavity of Crocodylus niloticus Laurenti (Reptilia: Crocodylidae), based on a detailed study of its morphology using light and scanning electron microscopy. The new species is compared with its congeners, M. australiensis Moravec, Kay & Hobbs, 2004, M. vazi Travassos, 1933 and M. vivipara von Linstow, 1906 from crocodilians, and with M. indica Khera, 1951 from chelonian hosts. It can be distinguished from these by the length of its spicules, which are longer than in all described species and a combination of characters, including the presence of prominent lateral caudal papillae on the level of the cloaca in males, the presence of conspicuous phasmids on the female tail, the pre-equatorial position of the vulva and the length of the first-stage larvae. Micropleura huchzermeyeri n. sp. is further characterised by having 14 cephalic papillae in both sexes and ten pairs of caudal papillae in males. This is the first report of a representative of the genus Micropleura von Linstow, 1906 from a crocodilian in the Afrotropical region. Micropleura helicospicula Dey Sarkar, 2003 is considered a species incertae sedis.     

Two new species of linebellies (Genus Pseudoscopelus) with a revised key of species (Perciformes: Chiasmodontidae)

The swallowerfishes previously identified as Pseudoscopelus altipinnis and P. cf. altipinnis (Prokofiev, Kukuev, 2005) are described as a complex of two new, closely-related, allopatric species having antitropical distribution. P. astronesthidens—superspecies is most closely related to P. altipinnis due to its dark orobranchial cavity and the details of its photophore arrangement, but is unique within the genus in the disconnection between the mxf and apf series of photophores and in the details of jaws dentition. P. astronesthidens sp. n. (North Atlantic) differs from P. australis sp. n. (Southern Hemisphere) mainly in the long upper jaw and pectoral fins and in the presence of the ppf series of photophores. P. altipinnis Parr, 1933 is considered as a senior synonym of P. microps Fowler, 1934. A revised key for identification of the linebellies of the genus Pseudoscopelus is given.     

Morphological variability of pond smelt <Emphasis Type="Italic">Hypomesus olidus</Emphasis> (Osmeridae) from some water bodies of the Far East

Morphological variability of four characters in 13 samples of pond smelt Hypomesus olidus is investigated using three parameters: fluctuating asymmetry, geographic variability, and variability of characters. The differences in the level of fluctuating asymmetry in H. olidus from various water bodies of the Far East and, thus, in the stability of development depend on the differences in conditions of embryonic and early postembryonic development. Only one character of four (mean number of soft rays in pectoral fins) shows presence of geographic variability in smelt: the mean value of this character increase from north to south. Estimation of variability of characters demonstrates that the maximum fluctuations of the variation coefficient are characteristic of the number of infraorbital bones and the minimal fluctuations are characteristic of the number of soft rays in pectoral fins.     

Two New Species of Goby of the Genus <Emphasis Type="Italic">Astrabe</Emphasis> from Japan

Two species of goby belonging to the genus Astrabe are described from Japan as new species, A. flavimaculata and A. fasciata. A. flavimaculata is distinguishable from A. lactisella, the type species and hitherto the only known species of the genus, in that it has no protrusion on the upper posterior part of the dermal fold along the upper margin of the eye, fewer scales in a longitudinal row, predorsal scales, scales on the belly, a narrower white transverse band across the base of the pectoral fins, and in life yellow markings on a dark brown ground colour except for the white transverse band across the base of the pectoral fins. A. fasciata is distinguishable from A. lactisella in that it has fewer scales in a transverse row, a narrower scaled area on the lateral side of the body, a narrower white transverse band across the base of the pectoral fins, and a white transverse band across the anterior part of the 1st dorsal fin extending to the ventral side of the body.     

<Emphasis Type="Italic">Argyripnus boreopacificus</Emphasis> sp. nova,a new species of hatchetfishes (Sternoptychidae) from the subtropical Northwestern Pacific

A new species of the genus Argyripnus is described from the underwater elevations of the Northwestern Pacific. The species is most similar to A. hulleyi from the western Indian Ocean, but it differs in a larger number of rays of the dorsal and pectoral fins, a slightly larger number of photophores in the ventral row, and several other characters. The type series of the species is the most northern record of the representatives of the genus in the Pacific Ocean.     

New species of the genus <Emphasis Type="Italic">Tryssogobius</Emphasis> (Gobiidae) from the tropical the Western Pacific with a complete set of pores of the seismosensory system on the head

A new species, Tryssogobius fisunovi sp. n., is described from the depth of 73 m in the region of the Anambas Islands (Indonesia), South China Sea. Based on the presence of the preopercular and orbito-scapular canals, the species is similar to T. porosus, but it differs from the latter species in coloration, location of the mental row of genipores f, separated pelvic fins, and other characters. The problems of the systematics of the genera Tryssogobius and Obliquogobius are discussed.     

Two new species of deepwater flathead <Emphasis Type="Italic">Bembras</Emphasis> Cuvier, 1829 from the Andaman Sea,eastern Indian Ocean

Two new species of Bembras Cuvier 1829, Bembras leslieknappi sp. nov. and Bembras andamanensis sp. nov., are described from single specimens collected from the Andaman Sea off Myanmar, eastern Indian Ocean, in 2015. The two new species are distinguished from each other and five known congeners by the numbers of anal-fin rays and pectoral-fin rays (15 and 20 in B. leslieknappi vs. 14 and 20–21 in B. andamanensis), forward-slanting body scale rows above the lateral line (80 vs. 74) and upper limb gill rakers (3 vs. 4), as well as by head (41.5 vs. 42.1% SL), snout (14.3 vs. 13.8% SL) and orbit (10.4 vs. 10.9% SL) proportions, and color of the second dorsal (dusky, with blackish spots only on first spine and bases of many soft rays vs. pale, with many scattered blackish spots), pectoral (with a blotch vs. without it) and caudal (both with a broad band) fins.     

First find of the uvenile specimen of rare lumpsucker species <Emphasis Type="Italic">Cyclopteropsis jordani</Emphasis> (Cyclopteridae) from the Kara Sea

The juvenile specimen of Cyclopteropsis jordani from the Kara Sea was first found and described. According to the trapezoid form of the first dorsal fin, the largest length of its median rays, slightly lateral compression of the body and the number of rays in the dorsal, anal and pectoral fins, the juvenile is classified as Cyclopteropsis jordani. From one-size juvenile of Eumicrotremus derjugini it is distinguished by the complete absence of bone plaques.     

Phylogenetic relationships of sculpin <Emphasis Type="Italic">Cottus volki</Emphasis> Taranetz, 1933 (Scorpaeniformes,Cottidae) according to the results of analysis of control region in mitochondrial DNA

Sequencing of the fragment of control region in mitochondrial DNA in sculpin Cottus volki and the comparison of obtained data with homologous nucleotide sequences in the other species from genus Cottus demonstrated that C. volki occupies the basal position in the “poecilopus” group, which includes also typical sculpin C. poecilopus Heckel, 1837 from water bodies of Europe, sculpin C. szanaga Dybowski, 1869 from the Amur River basin, and sculpin Cottus cf. poecilopus from the Lena River basin. Early separation of C. volki line from common trunk of “poecilopus” group explains the presence in C. volki of several primitive (plesiomorphic for this group) morphological characters: long interior ray of ventral fin, practically complete lateral body line, and well-developed dentition of palatine bones.     

New species <Emphasis Type="Italic">Amblyeleotris</Emphasis> (Gobiidae) from Phan Thiet Bay (South China Sea,Vietnam)

A new species Amblyeleotris memnonia sp. n. from the South China Sea is described. By the high number of rays in the second dorsal and anal fins, the new species is close to A. gymnocephala and A. cephalotaenia, but it differs from them and all other species by the uniform dark color of the body.     

Revision of <Emphasis Type="Italic">Rhabdolepis macropterus</Emphasis> (Bronn, 1829) (Osteichthyes,lower Actinopterygii; Lower Permian,SW Germany)

The neotype of Rhabdolepis macropterus is revisited. Together with additional material, a new reconstruction of the skull in lateral view is presented. Main characters of this species of the family Elonichthyidae are a ventral accessory operculum which completely separates the operculum from the suboperculum, and further the border between the frontal (parietal) and the parietal (postparietal) bones lying anterior to the border between the dermosphenotic and the dermopterotic bones. The diagnosis of genus Rhabdolepis is renewed. The species Rh. macropterus is compared with the sympatric elonichthyid species Rhabdolepis saarbrueckensis and Elonichthys fritschi.     

A new species of labrid fish <Emphasis Type="Italic">Oxycheilinus samurai</Emphasis> from the western Pacific Ocean

A new species of labrid fish Oxycheilinus samurai sp. nov. is described on the basis of five specimens from the Ryukyu Islands, Japan, and Panay Island, the Philippines. The new species is most similar to the Indo-West Pacific species Oxycheilinus orientalis in having a slender compressed body, 12 pectoral-fin rays, a blackish blotch around the anterior portion of the lateral-line anterior series, and a dark blotch basally on the membrane between the first and second dorsal-fin spines. However, O. samurai can be distinguished from O. orientalis by the following combination of characters: gill rakers 4 + 7–8; snout rounded with maximum circumference 49.8–63.5 % of standard length (SL); interorbital width 7.7–9.2 % of SL; caudal-peduncle depth 13.8–15.3 % of SL; posterior margin of caudal fin white; black or dark red area just before white posterior margin of caudal fin; poorly defined blackish blotches on inner surface of opercle in preserved specimens.