Mustura daral, a new species of stone loach from Arunachal Pradesh, Northeast India (Teleostei: Nemacheilidae).

Mustura daral, new species, is described from the Siang River (Brahmaputra drainage) in Arunachal Pradesh, Northeast India. The new species is distinguished from its congeners by: 910 dark-brown saddles on dorsum, each continued down on flank forming regularly set and shaped dark-brown bars; two black blotches at caudal-fin base; caudal fin forked with 9+8 branched rays; lateral line complete; median notch in lower jaw absent; axillary pelvic lobe large; and suborbital flap in male with conspicuous tubercles along posterior rim.

A new species of stone loach of the genus Mustura (Teleostei: Nemacheilidae) from Chindwin River drainage, Manipur, north-eastern India.

Mustura taretensis, a new nemacheilid loach, is described from the Taret River, a tributary of the Yu River, Chindwin River drainage, Manipur, India. The new species is distinguished from all its congeners by a unique combination of the following characters: body with 1213 irregular dark-brown blotches or bars on flank, alternating with 1116 irregular dark-brown saddles on the back; dorsum of head with a distinctly visible rhomboid dark-brown mark encircling a pale oval area on the nape; dorsal fin with 9 or 10 branched rays; lateral line complete; a well-developed free posterior chamber of air bladder, the halves of air bladder capsules connected by a manubrium; poorly developed processus dentiformis; suborbital flap present in males; and body depth 12.816.0 % SL. The generic status of Mustura chindwinensis, M. dikrongensis, M. tigrina and M. tuivaiensis are also discussed in the paper.

Exostoma kottelati, a new species of catfish (Teleostei: Sisoridae) from Arunachal Pradesh, India.

Exostoma kottelati, new species, is described from the Ranga River, Brahmaputra basin, in Arunachal Pradesh state, northeastern India. It differs from congeners in the Brahmaputra River basin in having a longer adipose-fin base (33.4-36.0 % SL vs. 23.4-32.9), a greater (except E. mangdechhuensis) pre-pelvic length (45.6-47.3 % SL vs. 39.3-44.6) and a greater pre-anal length (73.9-76.5 % SL vs. 62.2-70.1). It further differs from all known congeners by the following unique combination characters: the adipose fin is distinctly separated from the dorsal procurrent caudal-fin rays, pre-dorsal length 38.9-41.7% SL, adipose-fin base length 33.4-36 % SL, caudal peduncle length 18.7-21.1 % SL, caudal peduncle depth 8.8-9.5 % SL, and body depth at anus 12.5-13.5 % SL. This is the fifth species of Exostoma known from the Brahmaputra River basin.

A new species of the genus Garra Hamilton (Teleostei: Cyprinidae) from Northeast India.

A new species of Garra with a rostral proboscis is described from the Barak River drainage in Manipur, India. Garra paratrilobata, new species, is distinguished from its congeners in having the combination of the following characters: a prominent trilobed proboscis, the median lobe with 5-7 uni- to tricuspid tubercles on its anterior margin and 4-6 minute tubercles on its anteroventral margin; lateral lobe of the proboscis with 3-4 minute tubercles; lateral surface of the snout lobular, with 6-9 tubercles; 33-34 lateral-line scales; and the rostral surface concave, creased and depressed.

Mystus prabini, a new species of catfish (Siluriformes: Bagridae) from Arunachal Pradesh, north-eastern, India.

Mystus prabini, new species, is described from the Sinkin and the Dibang River in the Lower Dibang Valley District of Arunachal Pradesh, India. The new species differs from all South-Asian congeners except M. bleekeri, M. cavasius, M. zeylanicus,  M. falcarius, M. seengtee, M. cineraceus, M. ngasep, M. rufescens and M. ankutta in having a long adipose fin that reaches anteriorly (vs. distinctly does not reach) the base of the last dorsal-fin ray. The new species can be distinguished from the named nine species in having (vs. lacking) a narrow black mid-lateral stripe extending from the anterior region of tympanic spot to the rounded black spot at the caudal-fin base. The analysis of mitochondrial cytochrome c oxidase subunit I (COI) gene sequence shows that the K2P value between Mystus prabini and all other Mystus species ranges from 8.6-22.1%. Mystus prabini is closest genetically to M. bleekeri and M. albolineatus, from which species it has a genetic distance of 8.6% and 13.9%, respectively. The genetic distance (K2P) between the new species and M. dibrugarensis is 21.1%.

A new species of stone loach (Teleostei: Nemacheilidae: Schistura) from Arunachal Pradesh, India.

Schistura rebuw, new species, is described from the Kameng River, a north-bank tributary of the Brahmaputra, Arunachal Pradesh, India. The new species is easily distinguished from all known congeners in the Brahmaputra basin by its unique sexual dimorphism, specifically a suborbital slit in adult females, and a suborbital flap in adult males; and a colour pattern of 10-11 blackish bars on a greyish-beige body, the pre-dorsal bars mostly broken or incomplete, coalescing dorsally in a more or less alternate fashion.

A new species of the genus Garra (Teleostei: Cyprinidae) from the Barak River drainage, Manipur, India.

Garra substrictorostris, a new labeonine species, is described from the Barak River drainage in Manipur, India. It is distinguished from its congeners by the combination of the following characters: a prominent unilobed antrorse proboscis, with 3-5 medium to large multicuspid tubercles on its anterior margin; 4-6 multicuspid tubercles on its anteroventral margin; a prominent transverse lobe with 14-20 multicuspid tubercles; the lateral surface of the snout slightly elevated, lobular with 7-11 small tubercles; 5½ transverse scale rows above the lateral line and 3½ or 4½ scale rows between lateral line and anal-fin origin.

Pethia poiensis, a new species of cyprinid fish from the Chindwin Basin of Manipur, India.

Pethia poiensis, a new cyprinid species, is described from the Challou River, Chindwin Basin, Manipur, India. The new species is characterised by an incomplete lateral line with 7-9 pored scales, the absence of barbels, 19-20 scales in lateral series, 9-10 pre-dorsal scales, 18 pre-anal scales, 3½ scales between dorsal-fin origin and lateral line, three scales between lateral line and pelvic-fin origin and a unique colour pattern consisting of a humeral spot encompassing the third and fourth lateral-line scales, a caudal spot on the 16th and 17th lateral series scales and a black stripe along the flank. A revised key to the species of Pethia found in the Chindwin-Irrawaddy drainage is presented.

Molecular phylogenetic analysis of genus Osteobrama Heckel, 1843 and discovery of Osteobrama serrata sp. nov. from North East India.

Genus Osteobrama Heckel is characterized by strongly compressed, fairly deep body with abdominal edge sharp and trenchant entirely or from the pelvic fin base to vent; anal fin long with 14-36 rays, of which 11-13 are branched rays. The fishes of this genus are distributed in Pakistan, India, Bangladesh, Burma, and Yunnan (China). Present study involve six Osteobrama species viz. O. belangeri, O. cotio, O. cunma, O. feae, O. serrata sp. nov., and O. vigorsii. Out of the 655 positions analyzed in the COI sequence dataset, 171 positions (26.1%) were variable, and 151 positions (23%) were parsimoniously informative. The genetic distance between Osteobrama species ranges from 7.10% (between O. cotio and O. serrata sp. nov.) to 22.86% (between O. belangeri and O. feae) for COI sequences and 3.04% (between O. serrata sp. nov. and O. cunma) to 9.89% (between O. serrata sp. nov. and O. belangeri) for 16S sequences. Osteobrama belangeri show very high interspecies K2P distance with all other Osteobrama species for COI and 16S datasets. Best fit models for COI and 16S rRNA dataset were HKY + G + I and K2 + G, respectively. The maximum-likelihood (ML) phylogenetic trees were constructed using the COI and 16S rRNA sequences.

Garra clavirostris, a new cyprinid fish (Teleostei: Cyprinidae: Labeoninae) from the Brahmaputra drainage, India.

Garra clavirostris, a new cyprinid fish, is described from the Dilaima River, a tributary of the Brahmaputra in the Dima Hasao district, Assam. The new species is distinguished from all its congeners in northeast India in having a combination of the following characters: a prominent unilobed club-shaped proboscis overhanging the depressed rostral surface, with 5-9 medium to large uni- to multi-cuspid tubercles on the anterior margin and 5-6 uni- to multi-cuspid tubercles on the anteroventral marginal aspect; a prominent transverse lobe on the snout, with 17-25 small- to large-sized multicuspid tubercles; and presence of a black spot at the upper angle of the gill opening.

Parambassis serrata, a new species of glassperch (Teleostei: Ambassidae) from the Kaladan drainage, India.

Parambassis serrata, a new species of glassperch from the Kolo River, Kaladan drainage, Mizoram, India is described. It is distinguished from its congeners by the combination of characters that includes: presence of a faint, vertically-elongated brown humeral blotch; posterior margin of most spines of first dorsal fin proximally blackish; 14-16 dorsal and anal-fin branched rays; a black longitudinal stripe on ventral surface of caudal peduncle; absence of predorsal scales; a serrated preopercular ridge; 51-56 scales in lateral series; and 11 pectoral-fin rays.

Devario deruptotalea, a new species of cyprinid fish from Manipur, India (Teleostei: Cyprinidae).

Devario deruptotalea, a new cyprinid fish, is described from Dutah Stream, a tributary of the Yu River (Chindwin drainage) in Manipur, India. It is distinguished from all its congeners by a unique colour pattern consisting of the following combination of pigmented elements: 4‒6 dark brown irregularly shaped and arranged bars that are partly confluent with adjacent bars at different levels on the anterior one-third of the side of the body, followed by three distinct dark brown stripes posteriorly, a P stripe that is darker and about twice as broad as other stripes and extending to the tip of the median caudal-fin rays.

Schistura phamhringi, a new stone loach from Chindwin Basin in Manipur, India (Cypriniformes: Nemacheilidae).

Schistura phamhringi, new stone loach, is described from Dutah Stream, tributary of the Yu River (Chindwin basin), near Larong Village, Chandel District, Manipur, India. It is distinguished from all its congeners by a unique combination of characters: 6-7 black saddles, each continued on both flanks forming broad diamond-shaped black bars with narrow ventral margin; bars superimposed on a grey stripe along lateral line; upper lip with numerous melanophores; black basicaudal bar arc-shaped; complete lateral line; and prominent oar-like suborbital flap on male.

A new species of Psilorhynchus (Teleostei: Psilorhynchidae) from the Chindwin basin of Manipur, India.

Psilorhynchus chakpiensis, new species, is described from the Chakpi River, Chindwin basin in Manipur, India. It is distinguished from its congeners by a combination of characters: a dome-shaped rostral cap with horizontally arranged pointed tubercles, 1-2 rows of prominent globular papillae behind the upper lip, three unbranched and nine branched dorsal-fin rays, 30-31 lateral-line scales, head width 74-83% HL, and characteristic colour bands on the dorsal and caudal fins. It is distinguished from all congeners in having a caudal-fin pattern consisting of two black bars, one incomplete bar near the base of the upper lobe, and a complete bar across the centre of the fin, traversing from the upper to the lower margin of the fin.

A new species of the genus Pethia from Mizoram, northeastern India (Teleostei: Cyprinidae).

The paper describes Pethia expletiforis, a new cyprinid species from the Ka-ao River, Kaladan drainage, Mizoram, India. It is distinguished from its congeners in the Chindwin-Irrawaddy and Ganga-Brahmaputra drainages by the combination of: a complete lateral line, nine predorsal scales, 12 circumpeduncular scales, ½4/1/3½ transverse scales, a black blotch on the caudal peduncle, and the absence of a humeral mark and barbels.