<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 Data on MtDNA Variability of Pond Smelt <Emphasis Type="Italic">Hypomesus olidus</Emphasis> (Osmeridae) from the Commander Islands in Comparison with Other Populations of the Species

Sequencing of two regions of mitochondrial DNA, CytB (1124 bp) and COI (629 bp), is conducted for the first time for pond smelt Hypomesus olidus (Osmeridae) from the Commander Islands. The haplotypes identified, H1 and H2, differ by one mutation in the region of the COI gene. Haplotype H1 that belongs to the pond smelt from the Commander Islands was previously massively found in pond smelt of Azabache Lake. Haplotype H2 was not found previously and is probably unique to pond smelt from the Commander Islands.     

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.     

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.     

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.     

<Emphasis Type="Italic">Careproctus surugaensis</Emphasis> sp. nov. (Liparidae), a new snailfish from Suruga Trough,Japan

A new species of liparid fish Careproctus surugaensis is described from a single specimen collected between 1,450 and 1,570 m depth on the northern part of Suruga Trough, Suruga Bay, Japan. It can be distinguished from all currently recognized congeners by the following combination of characters: 50 total vertebrae, 47 dorsal-fin rays, 39 anal-fin rays, 32 pectoral-fin rays, 10 principal caudal-fin rays, pectoral proximal radials 4 (first to third with notches); trilobate teeth on both jaws, gill slit 7.1 % SL, extending in front of 7th pectoral fin ray base; maximum body depth 19.1 % SL, disk length 7.9 % SL, anus midway between posterior margin of pelvic disk and anal-fin origin; body and fins light orange except blackish peritoneum.     

Behavioral and morphological asymmetries in roach <Emphasis Type="Italic">Rutilus rutilus</Emphasis> (Cyprinidae: Cypriniformes) underyearlings

The underyearlings of roach, Rutilus rutilus, displayed a bilateral asymmetry of C-bend—the initial stage of escape behavior. Most individuals exhibited a significant bias to turn leftward or rightward after being stimulated by electrical current. This individual asymmetry was consistent when the same fish were retested ten days later. A significant correlation was revealed between the behavioral asymmetry and the bilateral asymmetry of surface area of frontal (positive correlation) and parietal (negative correlation) cranial bones. No significant correlation was found with the bilateral asymmetry of other morphological characteristics: numbers of pores of the seismosensory canals (praeopercular-mandibular, supraorbital, and supratemporal) in flat cranial bones (dental, praeopercular, frontal, and parietal numbers of lateral line pores, and numbers of rays in pectoral and ventral 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.     

Postglacial Colonization of the North European Seas by Pacific Fishes and Lamprey

A critical analysis of literature data on the distribution, morphology, and phylogeography of the Arctic lamprey (Lethenteron camtschaticum) and five species of marine and anadromous fish such as navaga (Eleginus navaga), pollock (Theragra chalcogramma), rainbow smelt (Osmerus mordax dentex), Pacific herring (Clupea pallasii), and pond smelt (Hypomesus olidus) has been performed. The results show that all these species have colonized Northern European seas, distributing along the Arctic coastline of Eurasia after the glacier retreat. The reasons that the dispersal of these species in the Atlantic Ocean may be impeded (preference for a cold environment, competition, and decrease of the evolutionary potential) are discussed.     

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.     

Pond smelt <Emphasis Type="Italic">Hypomesus olidus</Emphasis>, a new species of the ichthyofauna of the Commander Islands

The population of pond smelt Hypomesus olidus has been registered for the first time in the water bodies of Bering Island (Commander Islands). The spawning of this species has been observed in the Sarannoe Lake system, and the maturing breeders have been caught in the freshwater-brackish Gavanskoe Lake system. The spawning grounds, the spawning period, the environment, and the morphology of the breeders have been described. The ratio of Ca and Sr isotopes in the otoliths of the pond smelt inhabiting the Sarannoe Lake system evidenced that this species here was presented by the resident ecotype. The problem of the smelt phylogeny and resettlement in the northern Pacific Ocean is discussed.     

A new troglobitic loach <Emphasis Type="Italic">Triplophysa tianlinensis</Emphasis> (Teleostei: Nemacheilidae) from Guangxi,China

A new cave-dwelling species Triplophysa tianlinensis sp. nov. is described based on specimens collected from a karst cave in Hongxing Village, Langping Town, Tianlin County, Guangxi Zhuang Autonomous Region, China. The new species can be distinguished from its congeners by following a combination of characters: tip of pectoral fin not reaching pelvic-fin origin; body unpigmented, smooth and scaleless; dorsal fin with 8–9 branched rays, its origin anterior to pelvic-fin origin; black pigmented, rudimentary orbital spot; lateral line complete; 0+10 gill rakers on the first gill arch. Additionally, although the new species and Triplophysa langpingensis are from the cave of Langping Town, the new species could be distinguished from T. langpingensis by the following character: lateral line completed, 3+10 infraorbital and 15 preoperculo-mandibular pores.     

New record of the golden grouper <Emphasis Type="Italic">Saloptia powelli</Emphasis> (Perciformes: Serranidae) from North Sulawesi,Indonesia

One specimen (300 mm in standard length) of Saloptia powelli, belonging to the family Serranidae, was newly collected in a local fish market in Manado, North Sulawesi, constituting a new record for the species in the Indonesian archipelago. This species was diagnosed by the following morphological traits: dorsal rays VIII—11, anal rays III—8, well-defined opercular spines, pelvic fins below pectoral fins, caudal fin emarginate, mouth moderate in size, supplemental maxillary present, fine teeth in irregular rows on vomer and palatines. Head, body, and fins yellow in color. We suggest “kerapu emas”, a translation of its existing common name “golden grouper”, for the Indonesian species names.     

A comparison of different structures and methods for estimating age of northern-form Dolly Varden <Emphasis Type="Italic">Salvelinus malma malma</Emphasis> from the Canadian Arctic

Assessment of anadromous northern-form Dolly Varden Salvelinus malma malma in the Western Canadian Arctic requires reliable methods for estimating ages. Additionally, conservation efforts warrant determining whether fin rays provide a non-lethal alternative to otoliths. Precision and bias of whole and sectioned otoliths, and sectioned pectoral and pelvic fin rays were examined. Two age readers with different levels of experience ageing this species read each structure three times. Coefficient of variation (CV) was calculated to measure precision, and age bias plots were created for each method of preparation/structure within and between readers. The experienced reader demonstrated the highest precision with sectioned otoliths (CV = 1.6 %) followed by whole otoliths (CV = 4.2 %) while pectoral and pelvic fins were the lowest, CV = 7.7 % and 7.5 %, respectively. The age bias plot showed little difference between whole and sectioned otoliths, although greater imprecision/bias was evident for whole otoliths at age ≥9. Compared to otoliths, fin rays produced younger age estimates starting at 5 years; however, pelvic fins were more biased towards younger estimates than pectoral fins. The less experienced reader had greater inconsistencies, tending to overage younger and underage older samples for all methods compared to the more experienced reader, underscoring the importance of experience when estimating age for this species. We conclude that both types of fin rays are a poor non-lethal alternative to otoliths for fish ≥5 years and recommend an experienced ager could use whole otoliths up to age 8 and sectioned otoliths for fish ≥9 years (>500 mm fork length).     

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.     

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.     

Review of Indo-Pacific dwarf lionfishes (Scorpaenidae: Pteroinae) in the <Emphasis Type="Italic">Dendrochirus brachypterus</Emphasis> complex,with description of a new species from the western Indian Ocean

A taxonomic review of the Dendrochirus brachypterus complex resulted in the recognition of five species, including Dendrochirus barberi (Steindachner 1900), Dendrochirus bellus (Jordan and Hubbs 1925), Dendrochirus brachypterus (Cuvier in Cuvier and Valenciennes 1829), Dendrochirus hemprichi sp. nov. and Dendrochirus tuamotuensis Matsunuma and Motomura 2013. The complex is defined as having usually 9 dorsal-fin soft rays, usually 5 anal-fin soft rays, 17–20 (rarely 20) pectoral-fin rays, no ocellated spots on the soft-rayed portion of the dorsal fin and usually 2 (sometimes none) barbels on the snout tip. Dendrochirus barberi, known from the Hawaiian Islands and Johnston Atoll, is characterized by usually 18 pectoral-fin rays, a relatively high number of scale rows in the longitudinal series (modally 51 vs. 39–49 in other species) and mottled markings on the pectoral fin in large specimens. Dendrochirus bellus, restricted to the northwestern Pacific Ocean from the South China Sea north to southern Japan, is characterized by usually 17 pectoral-fin rays, a relatively low number of scale rows in the longitudinal series (modally 38 vs. 44–51 in other species), and the absence of skin flaps on the orbit surface and uppermost preopercular spine base. Dendrochirus tuamotuensis, recorded only from the Tuamotu Archipelago, is characterized by 19 pectoral-fin rays, the posterior margin of the pectoral fin strongly notched, and a relatively shallow and narrow head and body. Dendrochirus hemprichi sp. nov. is distributed in the western Indian Ocean, including the Red Sea. Although previously confused with a closely related congener (D. brachypterus, known from the northern and eastern Indian Ocean and western Pacific), D. hemprichi can be distinguished from the former by having fewer scale rows between the last dorsal-fin spine base and lateral line, and between the sixth dorsal-fin spine base and lateral line [4–7 (5) in D. hemprichi vs. 5–7 (6) in D. brachypterus, in both cases], a slightly greater interorbital width at the mid-orbit [5.5–10.7 (mean 7.8) % SL vs. 4.5–8.9 (6.8) % of SL] and at preocular spine base [4.4–9.1 (6.6) % SL vs. 3.5–7.8 (5.7) % of SL], and slightly shorter posteriormost (usually 13th) dorsal-fin spine length [11.8–19.9 (15.3) % SL vs. 13.3–21.3 (17.2) % of SL]. Moreover, D. hemprichi tends to have relatively more spinous points on the head spines and ridges, compared with D. brachypterus. Notwithstanding the morphological similarity between the two species, an obvious genetic difference was observed between D. hemprichi and D. brachypterus. Dendrochirus chloreus Jenkins 1903 and Dendrochirus hudsoni Jordan and Evermann 1903 were synonymized under Pterois barberi, as in some previous studies. Scorpaena koenigii Bloch 1789 was regarded as conspecific with D. brachypterus, which it predated. However, the former name should be suppressed under Reversal of Precedence.     

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.