Redescription of Polydactylus sexfilis (Valenciennes in Cuvier and Valenciennes, 1831), a senior synonym of P. kuru (Bleeker, 1853) with designation of a lectotype (Perciformes: Polynemidae)

Polydactylus kuru (Bleeker, 1853), originally described from Jakarta, Java, Indonesia, has been regarded as a valid species. However, examination of two syntypes of Polynemus kuru revealed their close similarity to three syntypes of Polynemus sexfilis Valenciennes in Cuvier and Valenciennes, 1831, in the synonym of which the former is herein included. Polydactylus sexfilis, which is widely distributed in the Indo-Pacific region, is redescribed on the basis of a newly-designated lectotype and two paralectotypes, and a wide range of non-type material. The species is characterized by six pectoral filaments, 15 or 16 pectoral fin rays, 61–67 pored lateral line scales, 8–10 scales above the lateral line, 12–14 below, 11–14 and 15–18 upper and lower series gill rakers, respectively (27–31 total), teeth present on vomer and a long second dorsal fin ray (mean 26% [range 21–30%] of standard length). Received: July 7, 2000 / Revised: August 29, 2000 / Accepted: September 30, 2000     

A new species of freshwater threadfin, <Emphasis Type="Italic">Polynemus aquilonaris</Emphasis>, from Indochina,and redescription of <Emphasis Type="Italic">Polynemus dubius</Emphasis> Bleeker, 1853 (Perciformes: Polynemidae)

 The taxonomic status of two nominal species of Polynemus, viz. P. dubius Bleeker, 1853 and P. longipectoralis Weber and de Beaufort, 1922, is revised. Although regarded as separate taxa up to the present time, examination of the holotype of P. longipectoralis revealed its close similarity to the type series of P. dubius, in the synonymy of which the former is now included. Polynemus dubius is redescribed as a valid species and a lectotype of the species is designated. In addition, a new species, P. aquilonaris, previously identified as P. dubius or P. longipectoralis, is described from Indochina on the basis of 28 specimens. Polynemus aquilonaris differs from P. dubius in having higher counts of pored lateral-line scales [80–86 (mode 81) vs. 69–79 (78) in the latter] and scale rows below the lateral line [14–17 (mode 14, rarely 13 or 17) vs. 13 (rarely 12)], and lower counts of gill rakers [25–29 (mode 27) vs. 29–33 (30), respectively]. The former is known from Indochina (Chao Phraya and Mekong River systems including Lake Tonle Sap), whereas the latter is currently known from the Malay Peninsula, Sumatra, and Kalimantan. Received: March 29, 2002 / Revised: February 2, 2003 / Accepted: February 10, 2003     

Review of seven-spined <Emphasis Type="Italic">Polynemus</Emphasis> species (Perciformes: Polynemidae) with designation of a neotype for <Emphasis Type="Italic">Polynemus paradiseus</Emphasis> Linnaeus, 1758

 A taxonomic review of seven-spined Polynemus species recognizes two species as valid: P. hornadayi Myers, 1936, currently known only from western Sarawak, Kalimantan, Malaysia, and P. paradiseus Linnaeus, 1758, distributed from India to Thailand and regarded as a senior synonym of P. aureus Hamilton, 1822, P. longifilis Cuvier in Cuvier and Valenciennes, 1829, P. risua Hamilton, 1822, and P. toposui Hamilton, 1822. Polynemus hornadayi differs from P. paradiseus in having a strongly protruded occipital profile (vs. nearly straight in the latter), lower counts of anal fin soft rays (mode 11 vs. 12) and gill rakers (26 vs. 32 or 33), higher counts of pectoral fin rays (18 vs. 17), scales above and below the lateral line (11 and 18 vs. 7 and 11, respectively), and pored lateral line scales (94 vs. 70), the fifth pectoral filament longest (vs. sixth), the fourth pectoral filament longer (extending well beyond the posterior central margin of the caudal fin vs. not reaching posterior central margin), a longer pectoral fin ray (posterior tip of pectoral fin reaching to midpoint of anal fin base vs. not reaching), a deeper maxilla posterior margin (mean 5% of SL vs. 4% of SL), and a well-developed swimbladder (vs. absent).     

Lepturacanthus roelandti (Bleeker, 1860), a valid species of hairtail (Perciformes: Trichiuridae)

A trichiurid, Lepturacanthus roelandti (Bleeker, 1860), previously regarded as a synonym of L. savala (Cuvier, 1829), is redescribed as a valid species on the basis of the holotype of the former and four non-type specimens. This species differs from the two valid congeners, viz., L. savala and L. pantului (Gupta, 1966), in having a gold sheen or yellowish-silver color when fresh (vs. steel-blue with metallic sheen in the latter two), posterior margin of maxilla reaching or extending beyond a vertical through hind eye margin (vs. not extending beyond a vertical through hind eye margin), pectoral fin slightly longer than snout (vs. slightly shorter than snout), tip of pectoral fin clearly extending beyond dorsal outline when vertically orientated (vs. not reaching dorsal outline), gill rakers absent or reduced to stiff ossified structures (vs. well developed, spinelike), first anal fin spine situated below the 40th–43rd dorsal fin ray (vs. below 35th–39th in L. pantului and 35th–40th in L. savala), precaudal vertebrae 42–43 (vs. 35–39 in L. pantului and 36–40 in L. savala), and attaining larger sizes [882–1200 mm in total length (TL) vs. less than 800 mm TL in the latter two].     

A new subspecies, Polynemus melanochir dulcis, from Tonle Sap Lake, Cambodia, and redescription of P. m. melanochir Valenciennes in Cuvier and Valenciennes, 1831 with designation of a neotype

 A poorly known threadfin, Polynemus melanochir Valenciennes in Cuvier and Valenciennes, 1831, is redescribed (as P. melanochir melanochir) on the basis of a newly designated neotype and a large number of specimens. Polynemus melanopus Sauvage, 1881 and 3 species commonly regarded as valid, Galeoides microps Steindachner, 1869, P. borneensis Bleeker, 1857, and Trichidion hilleri Fowler, 1905, are all considered junior synonyms of P. m. melanochir. In addition, a new subspecies, P. melanochir dulcis, is described on the basis of 3 specimens. Polynemus m. dulcis differs from P. m. melanochir in having a greater snout length [7% of SL vs. mean 6% (range 5–6%) of SL in the latter] and shorter upper caudal-fin lobe length [35% (34–35%) of SL vs. 39% (35–44%) of SL]. The former is currently known only from Tonle Sap Lake, Cambodia, whereas the latter is known from the Mekong River (Cambodia and southern Vietnam) and Kalimantan (=Borneo; Malaysia and Indonesia). Received: September 27, 2001 / Revised: December 20, 2001 / Accepted: December 29, 2001     

A new species, Polydactylus siamensis, from Thailand and redescription of P. plebeius (Broussonet, 1782) with designation of a neotype (Perciformes: Polynemidae)

A new species, Polydactylus siamensis, is described on the basis of eight specimens from Thailand. The species is similar to P. plebeius (Broussonet, 1782) in having five pectoral filaments and several dark stripes along the scale rows above and below the lateral line, but differs from the latter in having lower counts of pectoral fin rays (15 vs. 16–18 in P. plebeius), pored lateral line scales (54–58 vs. 60–68), scale rows above and below the lateral line (7 and 10 or 11, respectively vs. 8 or 9 and 12 or 13, respectively) and gill rakers (9 or 10 upper series, 13 or 14 lower and 22–24 total vs. 9–14, 13–18 and 24–32, respectively), and a longer upper jaw (mean 17% [range 16–17%] of standard length vs. 15% [13–16%]). Polydactylus siamensis is currently known only from Bangkok and Songkhla, Gulf of Thailand, and Phuket Island, Andaman Sea, whereas P. plebeius is widely distributed in the Indo-Pacific. Received: January 12, 2000 / Revised: September 15, 2000 / Accepted: January 12, 2001     

The Saurida undosquamis group (Aulopiformes: Synodontidae), with description of a new species from southern Japan

Four lizardfishes of Saurida (family Synodontidae), S. undosquamis, S. umeyoshii sp. nov., S. macrolepis, and S. longimanus, are described. All are recognized here as the Saurida undosquamis group, characterized by having dark dots on the upper margin of the caudal fin, pectoral fin exceeding origin to pelvic fin, anterior rays of dorsal fin neither elongate nor filamentous, predorsal length greater than distance between dorsal-fin and adipose-fin origins, 46–55 pored lateral-line scales, and vomer with 0–8 teeth. Saurida undosquamis, from northern West India and West Pacific, excluding East Asia, differs from others in having lateral-line scales ridged on the caudal peduncle, conspicuously concave posterior margin of the pectoral fin, 51–55 pored lateral-line scales, and 50–53 vertebrae. Saurida umeyoshii sp. nov., from southern Japan and the East China Sea, is defined by three rows of indistinct dark blotches on, above, and below the lateral line, distribution of scale pockets with melanophores on their posterior part extending over the entire abdominal region from the lateral line in specimens over ca. 130 mm SL, lateral-line scales not ridged on caudal peduncle, 49–52 pored lateral-line scales, and 48–50 vertebrae. Saurida macrolepis, from the Indo-West Pacific, is characterized by 46–49 pored lateral-line scales and 45–48 vertebrae. Saurida longimanus, from northern West India, northwest Australia, and southern Indonesia, differs from the others in having a long pectoral fin extending past the origin of the dorsal fin. Some geographic variations are found in S. macrolepis. Saurida grandisquamis is confirmed as a junior synonym of S. undosquamis, based on examination of the type specimens. A key to species in the S. undosquamis group is included.     

<Emphasis Type="Italic">Pyrolycus manusanus</Emphasis>, a new genus and species of deep-sea eelpout from a hydrothermal vent field in the Manus Basin,Papua New Guinea (Zoarcidae,Lycodinae)

A new genus and species of deep-sea zoarcid fish, Pyrolycus manusanus, is described on the basis of eight specimens collected from a hydrothermal vent field in the Manus Basin, Papua New Guinea, at depths of 1623–1971 m. This genus is distinguished from other scaleless eelpout genera in the subfamily Lycodinae by the following combination of characters: six suborbital bones; six to seven suborbital pores; flesh gelatinous; gill slit large, extending ventrally beyond pectoral fin base; three postorbital pores; single occipital pore; two to three pelvic fin rays; palatopterygoid series weak; vomer and palatine teeth present; pseudobranch, scales, lateral line absent; pyloric caeca present; 16–17 pectoral fin rays; 22–23 + 56–59 = 78–81 vertebrae. Received: August 5, 1999 / Revised: July 5, 2001 / Accepted: August 26, 2001     

Histological profiling of gonads depicting protandrous hermaphroditism in Eleutheronema tetradactylum

The fourfinger threadfin Eleutheronema tetradactylum is reported as a protandrous hermaphrodite from Australian waters, while being a gonochorist in reports from Singapore and India, with a single report of protandrous hermaphroditism from the latter. Histological analysis of gonads of fish from Indian waters confirms protandrous hermaphroditism in E. tetradactylum. The study was based on 480 fish examined from eight locations along the Indian coast. Mean total length (L_T) of male fish was 240 mm with the transition to female starting from 280 mm L_T. Specimens confirmed as mature females were >380 mm L_T.     

Redescription of <Emphasis Type="Italic">Bregmaceros mcclellandi</Emphasis> Thompson, 1840 (Gadiformes: Bregmacerotidae)

 This study redescribes Bregmaceros mcclellandi Thompson, 1840, based on one specimen (74.4 mm SL) from the Bay of Bengal and 66 specimens (30.0–84.7 mm SL) from Mumbai (Bombay), India, because the type specimens have apparently been lost. The present specimens are characterized by having black dorsal, pectoral, and caudal fins and show the following morphology: caudal fin slightly forked; body chromatophores present mainly at the dorsal part; no scales on cheek; vertebrae 52–55 (13–15 + 38–41); dorsal rays 52–59; anal rays 54–60; pectoral rays 18–20; caudal rays 27–31 (principal rays 14); transverse scales 14–15. In the 66 Mumbai specimens, it was confirmed that the distinctive black fin pigmentation developed sequentially with growth, with complete pigmentation first on the anterior lobe of the dorsal fin, then simultaneously on the posterior lobe of the dorsal fin, the caudal fin, and the pectoral fin, and last, on the anal fin. This species is known only from the Arabian Sea, Bay of Bengal, and Gulf of Thailand. A review of 16 nominal Bregmaceros species indicates that, besides B. mcclellandi, the distinctive dark fin pigmentation is found in B. atripinnis (Tickell), B. atlanticus Goode and Bean, B. japonicus Tanaka, and B. lanceolatus Shen. B. atripinnis is considered a junior synonym of B. mcclellandi, and the others are clearly distinct from B. mcclellandi. Comments are made on some of the characters to more fully characterize the species and for reference in future revisionary and phylogenetic studies. Received: June 17, 2002 / Revised: December 2, 2002 / Accepted: December 24, 2002     

<Emphasis Type="Italic">Epigonus carbonarius</Emphasis>, a new species of deepwater cardinalfish (Perciformes: Epigonidae) from the Marquesas Islands,with a redefinition of the <Emphasis Type="Italic">Epigonus oligolepis</Emphasis> group

A new epigonid fish, Epigonus carbonarius, is described on the basis of four specimens (50.8–95.3 mm standard length) collected from off Nuku Hiva Island, Marquesas Islands. This species belongs to the Epigonus oligolepis group, redefined in this study. It is distinguished from the three recognized species of the group by the following combination of characters: a small number of total gill rakers (21–23) and pyloric caeca (6), presence of lingual teeth, and absence of teeth from posterior part of vomer. A key to the species in the E. oligolepis group is provided.     

Validity of <Emphasis Type="Italic">Scolecenchelys aoki</Emphasis>, with a redescription of <Emphasis Type="Italic">Scolecenchelys gymnota</Emphasis> (Anguilliformes: Ophichthidae)

The myrophine ophichthid fishes (worm eels) Muraenichthys aoki Jordan and Snyder 1901 and Muraenichthys gymnotus Bleeker 1857 are redescribed as valid species of Scolecenchelys based on the types and non-type specimens collected from the Indo-Pacific. Because both species are similar to each other in having acute snouts, the posterior margin of the eye before the rictus, and their dorsal-fin origins located slightly posterior to a vertical line through the anus, Scolecenchelys aoki has usually been regarded as a junior synonym of Scolecenchelys gymnota. However, S. aoki is clearly distinguishable from S. gymnota by having a median groove on the ventral side of snout (absent in S. gymnota), uniserial maxillary teeth in smaller specimens (<200 mm TL; vs. biserial), three infraorbital sensory pores at postorbital area (vs. two), and more numerous vertebrae (56–65 in predorsal vs. 51–57; 53–58 in preanal vs. 47–52). Scolecenchelys aoki is restricted to Japanese waters and regarded as a senior synonym of Muraenichthys borealis Machida and Shiogaki 1990. Scolecenchelys gymnota is widely distributed in the Indo-Pacific, from South Africa and the Red Sea to Samoa, north to Okinawa, Japan. Sphagebranchus huysmani Weber 1913 and Muraenichthys fowleri Schultz 1943 are synonymized under S. gymnota.     

A new blind loach, <Emphasis Type="Italic">Oreonectes elongatus</Emphasis> sp. nov. (Cypriniformes: Balitoridae) from Guangxi,China

A new loach, Oreonectes elongatus sp. nov. is described based on collections from Mulun Township, Huanjiang County, Guangxi in China. It is distinguished from its congeners by the combination of the following characters: most elongate body (body depth/SL 8.62–10.68%), blind, a forked caudal fin, obvious adipose dorsal crest and ventral crest; entire body naked and de-pigmented. Although the new species has a similar distribution with O. macrolepis, it can be distinguished by scales (absent in O. elongatus vs. present in O. macrolepis), shape of snout (elongate vs. round), the opposite position of the dorsal and pelvic fins origins (behind vs. front). The new species shares the same possession of dorsal and ventral crests, a forked caudal fin, eyeless, naked body and incomplete lateral line with O. translucens, but can be distinguished from the latter by caudal fin crest (more developed and translucent in O. translucens), longer anterior nostril tube and barbel, extreme of pectoral fin reaching 2/3 of the distance between origin of pectoral and pelvic fins, more vertebrae (4 + 38–39 vs. 4 + 32).     

A new silverside, <Emphasis Type="Italic">Atherinomorus aetholepis</Emphasis> sp. nov., from the West Pacific (Atheriniformes: Atherinidae)

Atherinomorus aetholepis sp. nov. is described from the holotype and 51 paratypes, 44–72 mm in standard length, collected from Indonesian and Philippine waters. The species is similar to other congeners in general body appearance, especially A. duodecimalis and A. regina, in having a slender body, a tubercle on the posterior end of the dentary, and a narrow midlateral band, but clearly differing from them in having a long spatular outgrowth on the posterior margins of most of the predorsal and interdorsal scales. Additionally, the species differs from A. duodecimalis in having a more slender body [body depth 17–22 (mean 19) % SL vs. 19–25 (mean 22) % SL], more midlateral scales [37–40 (mean 38.4) vs. 35–38 (mean 36.6)], more total vertebrae [38–42 (mean 39.9) vs. 36–40 (mean 38.0)], and fewer lower gill rakers [18–22 (mean 20.2) vs. 20–25 (mean 22.3)], and from A. regina in having more anal fin soft rays (12–14 vs. 9–10). Electronic supplementary material to this article is available at and accessible to authorized users. Received: October 22, 2001 / Revised: March 14, 2002 / Accepted: March 26, 2002 An erratum to this article is available at .     

A new species of <Emphasis Type="Italic">Rhinogobius</Emphasis> (Teleostei: Gobiidae) from the Julongjiang Basin in Fujian Province,China

Ten specimens of a new freshwater goby, Rhinogobius longyanensis were collected from the small tributary of the Julongjiang Basin, Fujian Province, southeastern China. The new species can be distinguished from all congeneric species by following unique combination of features: second dorsal fin rays I, 8; anal fin rays I, 7–8; pectoral fin rays modally 17; longitudinal scale series 30–32; predorsal scales 6–8; vertebral count 10 + 17 = 27; three parallel, deep brown oblique stripes crossing on cheek; branchiostegal membrane with 24–28 orange red spots in male; body with 5–6 deep brown blotches; pectoral fin base with a blackish brown bar. A diagnostic key to all nominal species with high vertebral counts from mainland Southeast Asia, China, Taiwan, and Japan is also provided.     

Length–weight relationships of six tropical fish species from Chilika Lagoon,India

The length weight relationships (LWRs) of six tropical fish species from Chilika Lagoon, India were studied. Specimens were caught using a wide range of fishing gear operated in the lagoon from January to December 2014. The fresh specimens were measured for total length and weight, then dissected and the sex confirmed. Previously unavailable in FishBase, the detailed LWRs of Daysciaena albida, Eleutheronema tetradactylum, Etroplus suratensis and Mystus gulio are reported for the first time. Maximum total lengths reported for Nematalosa nasus and Osteogeneiosus militaris in this study are new records for these species. The existence of a differential growth between male and female O. militaris was confirmed, which was not known earlier.     

A new righteye flounder, Poecilopsetta pectoralis (Pleuronectiformes: Poecilopsettidae), from New Caledonia

A new righteye flounder, Poecilopsetta pectoralis, is described from 4 specimens (2 males, 2 females) collected from deep waters (510–580 m) around New Caledonia. The species is easily distinguished from 13 congeners by having 99–105 lateral line scales, a narrow interorbit [male: 37.00–40.25 in head length (HL); female: 47.33–50.71], long pectoral fin on ocular side (male: 0.89–0.91 in HL; female: 1.04–1.20), no scales from snout to anterior interorbital region, and 4 spots on caudal fin. Sexual dimorphism is evident in this species, showing males bearing the ocular-side pectoral fin longer than females, and it is the first example in Poecilopsetta.     

Echiodon anchipterus: A valid western Pacific species of the pearlfish family carapidae with comments onEurypleuron

The collection of an adult specimen ofEchiodon from Owase, Japan, enabled us to further evaluate one of the unresolved identification problems listed by Markle and Olney (1990). The recognition ofEchiodon anchipterus Williams as a valid western Pacific species was questioned by Markle and Olney (1990), who tentatively synonymized it with the western Indian OceanE. coheni Williams. The Japanese specimen had 15–16 pectoral fin-rays (vs. 18 inEchiodon coheni), 22 total nasal lamellae (vs. 24), and 21 precaudal vertebrae giving a range forE. anchipterus of 19–21 (vs. 18–19). These new data support the recognition of bothE. anchipterus andE. coheni as valid, allopatrically distributed species. The phylogenetic relationships among the species ofEchiodon are reexamined and a cladogram summarizing our hypothesis of their interrelationships is presented. Eurypleuron owasianum (Matsubara) is considered to be endemic to the Japan Zoogeographic region, where adults are known only from specimens taken off Owase, Japan. The South African, southeastern Australian, New Zealand, and Sala y Gomez Ridge specimens are collectively referred toEurypleuron cinereum (Smith) pending a comprehensive revision of the group.     

A new species of <Emphasis Type="Italic">Penopus</Emphasis> (Teleostei: Ophidiidae) from the Ryukyu Trench,the West Pacific,with remarks on <Emphasis Type="Italic">Penopus microphthalmus</Emphasis>

The bathyal genus Penopus (Ophidiidae) is revised based on 23 specimens. One specimen from the Ryukyu Trench represents a new species, Penopus japonicus. The remaining 22 specimens were found on both sides of the Atlantic Ocean, and neither 28 meristic and morphometric characters nor several morphological characters show any differences between the two populations. This supports Séret (1988), who considered Penopus macdonaldi Goode and Bean 1896 a junior synonym of Penopus microphthalmus (Vaillant 1888). The new Japanese species can be separated from the Atlantic species by having fewer rays in the dorsal (117 vs. 135–158) and anal (89 vs. 106–122) fins, the squamation of the head restricted to the middle part of the preopercle versus the squamation covering the dorsum, preopercle and the opercle in part, a distinct spine behind the posterior nostril versus the spine hardly visible and 9 spines on the hind margin of the preopercle versus 4–7 spines.     

Descriptive morphology of the eggs,larvae, and juveniles of two cyprinid fishes belonging to the <Emphasis Type="Italic">Zacco temminckii</Emphasis> species' group

 Embryonic, larval, and juvenile development of two cyprinid species belonging to the Zacco temminckii species' group, Z. temminckii (Temminck and Schlegel) and Zacco sp. (type A), are described and compared with each other from laboratory-reared and wild specimens. The eggs of both species were closely similar except in diameter [1.92–2.20 mm in Z. temminckii vs. 1.60–1.75 mm in Z. sp. (type A)], being demersal, almost spherical in shape, transparent and unpigmented, with a pale yellow yolk, and no oil globule. Hatching occurred 40–53 h after fertilization in Z. temminckii and after 47–60 h in Z. sp. (type A). The newly hatched larvae of both species [4.9–5.3 mm in body length (BL) in Z. temminckii and 3.5–4.8 mm BL in Z. sp. (type A)] also resembled each other, having a large transparent pear-shaped yolk and lacking body pigmentation. Myomere counts of Z. temminckii and Z. sp. (type A) larvae and juveniles were 24–27 + 14–17 = 41–42 and 23–27 + 14–17 = 40–41, respectively. The yolk was completely absorbed at 8.3 mm BL in Z. temminckii and at 6.6 mm BL in Z. sp. (type A). Notochord flexion was initiated and completed at 7.8 mm BL and 8.2 mm BL in Z. temminckii and at 6.3 mm BL and 6.6 mm BL in Z. sp. (type A), respectively. Aggregate numbers of all fin rays were completed at 17 mm BL in Z. temminckii and 13 mm BL in Z. sp. (type A). Although the morphology of larvae and juveniles of both species was very similar, differences in body length of each developmental stage, the duration and process of disappearance of the adipose finfold, the anal fin ray counts, and pigmentation on the lateral body surface were clearly recognized. Received: August 10, 2001 / Revised: March 14, 2002 / Accepted: March 27, 2002