Unbranched Dorsal-fin Ray Research Articles

Pethia aurea (Teleostei: Cyprinidae), a new species of barb from West Bengal, India, with redescription of P. gelius and P. canius.

Fishes currently assigned to Pethia gelius Hamilton from West Bengal are shown to belong to a closely-related group of three species: P gelius, its erstwhile synonym P canius Hamilton and a new species, P aurea. The three species are distinguished from all other species of Pethia by having the lateral line incomplete, with 3-4 pored scales; 20-26 scales in lateral series on body; ½4-5/l/2-3½ scales in transverse line on body; 8-9 predorsal scales; barbels absent and by a unique colour pattern consisting of two or three black blotches on the body (which, however, fade on preservation), the first behind the opercle, the second beneath the origin of the dorsal fin, extending to the mid-lateral region, and the third above the origin of the anal fin. A black spot is also present at the base of the dorsal and anal fins. Additionally, P gelius is distinguished by having the last unbranched dorsal-fin ray thick, straight, serrated, with 20-25 serrae on its posterior margin; a snout length of 6.1-8.4% standard length (SL); a body depth of 32.6-37.7% SL; and a dorsal-fin height of 19.4-22.8% SL. Pethia canius is additionally distinguished by having a snout length of 8.9-11.8% SL; a body depth of 28.1-32.2% SL; and dorsal-fin height of 26.9-32.8% SL. Pethia aurea, new species, is additionally distinguished from all its congeners by having ½5/1/3-3½ scales in transverse line on body; 9 pre-dorsal scales; and last unbranched dorsal-fin ray slender, serrated, with 19-22 serrae on posterior margin.

Description of two new species and revision of Schizothorax distributed in the Irrawaddy drainage area in China

The Irrawaddy River crosses international borders throughout South-Eastern Asia, though several heads of different streams connected to the river are found in China. In the present study, two species never previously described were identified during taxonomic works on Schizothorax species distributed in the Irrawaddy drainage area in China, and were named Schizothorax leukus sp. nov. and Schizothorax heteri sp. nov. Schizothorax leukus can be distinguished from its congeners by a combination of the following characters: surface of lower lip covered with papilla, posterior edge of lower lip straight; low jaw developed, almost full the oral cavity, anterior edge of low jaw covered with horny sheath; breast and belly before pectoral-fin tip scaleless; barbels equal to eye diameter; last un-branched dorsal fin ray soft, lower third of the ray enlarged with posterior edge serrated; lateral line scales 94-105, scales between dorsal-fin origin to lateral line 26-34, scales between pelvic-fin origin to lateral line 21-27; outer side of the first gill arch with 16-20 gill rakers; body dark brown, without dark spots. Schizothorax heteri can be distinguished from its congeners by a combination of the following characters: rostral fold equal to upper lip; lower lip developed, trilobed, the median lobe minute, its width equal to diameter of the rostral barbel base; postlabial groove continuous; low jaw without horny sheath; breast and belly before pectoral-fin tip scaleless; barbels equal to eye diameter; last un-branched dorsal fin ray strong, posterior edge serrated; dorsal-fin origin posterior to pelvic-fin origin; lateral line scales 89-104, scales between dorsal-fin origin to lateral line 24-33, scales between pelvic-fin origin to lateral line 19-29; body light brown, without any spots. Likewise, we discuss the validation of S. rotundimaxillaris and the questionable records of S. molesworthi, S. griseus and S. paoshanensis. In total, eight valid species of Schizothorax were found and recorded from the Chinese Irrawaddy drainage area, with a key for identification is provided.

A new species of Tyttocharax (Characiformes: Characidae: Stevardiinae) from the Güejar river, Orinoco river Basin, Colombia

A new Tyttocharax species from the Güejar River system, near the Macarena Mountains in Colombia is described. This is the first record for the genus from the Orinoco basin. The combination of the following characters distinguish Tyttocharax metae from its congeners: presence of bony hooks on the pectoral and caudal-fin rays; bony hooks on the anal-fin rays larger than those on the pelvic-fin rays; pectoral-fin rays i,5-6,i; presence of three unbranched dorsal-fin rays; absence of an adipose fin; four scales rows between the anal-fin origin and the lateral line; and four scale rows between the pelvic-fin and the lateral line. Ecological characteristics of the habitat of the new species are also presented.

A new species of Barbine genus Sinocyclocheilus (Teleostei: Cyprinidae) from Zuojiang River drainage in Guangxi, China

A new species of the genus Sinocyclocheilus is described based on specimens collected from Zuojiang River drainage, Guangxi, China. The new species, named Sinocyclocheilus jinxiensis, is distinguished from all congeners by its vestigial eyes, short barbels, long pectoral fin, eight to nine branched dorsal-fin rays, last unbranched dorsal-fin ray soft with serrations on posterior edge of its lower part, and 38–41 lateral line scales.

A new early cyprinin from Oligocene of South China

Here we describe °Huashancyprinus robustispinus, gen. et sp. nov, a fossil cyprinin fish from the Oligocene of Ningming Basin, Guangxi, South China. It differs from all other cyprinin fishes in the following apomorphic characters: extremely robust last unbranched dorsal and anal fin rays with very fine serrations along posterior edge, the crowns of pharyngeal teeth A2 and A3 with a number of deep grooves on the lateral wall, rather large A3, and relatively deep infraorbital 2. Among the members of the Tribe Cyprinini sensu stricto, it mostly resembles the extant genus Cyprinus, particularly to species Cyprinus micristius and C. fuxianensis, which are restricted to Yunnan, southwestern China. The discovery of the cyprinin °Huashancyprinus from southern China, along with the previously known late Eocene °Cyprinus maomingensis, indicates an early branching of the Cyprininae (Cyprinidae) in this area.

The identity of Schizothorax griseus Pellegrin, 1931, with descriptions of three new species of schizothoracine fishes (Teleostei: Cyprinidae) from China

The identity of Schizothorax griseus Pellegrin, 1931, is clarified and the species redescribed. Three new species previously identified as S. griseus are described: S. nudiventris, from the Lancang Jiang, China; S. heterophysallidos, from the Nanpan Jiang, China; and S. beipanensis, from the upper Beipan Jiang, China. The group comprising Schizothorax griseus, S. nudiventris, S. heterophysallidos and S. beipanensis can be diagnosed from other members of this genus by the absence of an obvious horny sheath on the lower jaw; lower lip developed with three labial lobes in mature individuals; postlabial groove continuous, with a small labial lobe present in the middle of the lower lip; last unbranched dorsal-fin ray strong, its posterior edge with numerous serrae; and scales absent on ventral surface between pectoral fins in adults (except in S. griseus). Schizothorax griseus differs from S. nudiventris, S. heterophysallidos and S. beipanensis by the presence (vs. absence) of concealed scales in the skin on the ventral surface between the pectoral fins in adults; the presence (vs. absence) of a shallow ethmoidal groove before the nostrils; and having barbels much longer than eye diameter (eye diameter 33.4–93.7 % (vs. 57.2–160.0) of maxillary-barbel length). Schizothorax nudiventris is distinguished from S. heterophysallidos and S. beipanensis in having only the proximal ¾ (vs. entirety) of the last unbranched dorsal-fin ray strong; pelvic-fin origin opposite or posterior (vs. opposite or anterior) to vertical through dorsal-fin origin; and irregular black spots present (vs. absent) on side of body. Schizothorax heterophysallidos is distinguished from S. griseus, S. nudiventris and S. beipanensis in having a larger posterior chamber of the air bladder (vs. posterior chamber as large as, or slightly larger than, anterior one), length of posterior chamber 3–6 (vs. 2) times length of anterior chamber. Schizothorax beipanensis is distinguished from S. griseus by the absence (vs. presence) of scales on the thorax in mature individuals; absence (vs. presence) of black spots on side of body; and having the maxillary barbel 58.5–120.1 % SL (vs. 33.4–93.7 % SL).

Two New Species of Puntius from Northern Myanmar (Teleostei: Cyprinidae)

Puntius tiantian is described from Putao in northernmost Myanmar, diagnosed by having a dark vertical bar anteriorly on the side, a dark blotch on the caudal peduncle, slender and weakly serrated last unbranched dorsal fin ray, and complete lateral line. Puntius didi is described based on material from Myitkyina and Indawgyi Lake. It is similar to P. tiantian in color pattern, but possesses a thicker and more strongly serrated last unbranched dorsal fin ray, and a shorter lateral line perforating only 6–10 scales. The single record of P. phutunio from Myanmar most likely represents misidentified P. didi.

Molecular and morphological data suggest that Spinibarbus caldwelli (Nichols) (Teleostei: Cyprinidae) is a valid species

The taxonomic problem of the cyprinid species of genus Spinibarbus, occurring in southern China and northern Vietnam, was resolved on the basis of molecular and morphological analyses. Spinibarbus caldwelli and Spinibarbus hollandi have a smooth posterior edge of the last unbranched dorsal fin ray among species in the genus. Spinibarbus caldwelli is currently regarded as a junior synonym of S. hollandi because of ambiguities in diagnostic characters. In this article, 11 mtDNA cytochrome b sequences of Spinibarbus specimens were analyzed together with Barbodes gonionotus and Puntius conchonius as outgroups. Our results showed that specimens identified as S. hollandi from Taiwan were different from those from the Asian mainland at a high level of genetic divergence (0.097-0.112), which is higher than that between the two valid species, S. sinensis and S. yunnanensis ( 0.089), and suggested that Taiwan specimens should be considered as a different species from the Asian mainland one. In a molecular phylogenetic analysis, the sister-group relationship between Taiwan specimens and the Asian mainland specimens was supported strongly by a high confidence level ( 100% in bootstrap value). Further analysis of morphological characters showed that overlap of diagnostic characters is much weaker than previously suggested. Taiwan specimens had 8 branched rays in the dorsal fin, whereas those from the mainland had almost 9-10. The molecular and morphological differences suggest S. caldwelli to be valid. The molecular divergence shows the genetic speciation of S. hollandi and S. caldwelli might have occurred 5.6-4.9 million years ago; the former could be a relict species in Taiwan, and the latter dispersed in the Asian mainland.

Revision of the species of Priolepis possessing a reduced transverse pattern of cheek papillae and no predorsal scales (Teleostei; Gobiidae)

We recognize 10 species in this group of Priolepis, 4 of which are described here. Priolepis ailina n.sp. is known only from Moorea in the Society Islands, Priolepis kappa n.sp. ranges from the Comoro Islands (Comores) to Fiji, Priolepis latifascima n.sp. occurs in Taiwan and Japan, and Priolepis vexilla n.sp. is from Indonesia and the Philippine Islands. Among the previously described species, P. boreus occurs in Taiwan and Japan, P. compita ranges from South Africa to the Marquesas Islands, P. farcimen is restricted to the Hawaiian Islands, P. nocturna ranges from the Comores to the Marquesas, P. nuchifasciatus is found from Australia to Hong Kong and Singapore, and P. semidoliatus is present from the Red Sea to Pitcairn Island. We hypothesize that the clade is monophyletic, based on the loss of predorsal scales, and further, that P. nocturna forms the sister-group of the remaining species, all of which have lost the pectoral fin base scales. Priolepis ailina and P. kappa appear to be sister-species, based on the unique union of the opercular and postocular bars. The presence of at least some unbranched dorsal-fin rays appears to unite the remaining species, although this forces us to postulate a reversal in P. nuchifasciatus, in which the dorsal rays are branched. However, the joining of the bars over the pectoral-fin base and the opercle unites P. compita, P. farcimen, P. latifascima, P. nuchifasciatus, P. semidoliatus, and P. vexilla in a monophyletic group, to the exclusion of P. boreus. Within this clade, P. nuchifasciatus and P. vexilla are sister-species, based on the atavistic presence of a pelvic fraenum.