Description of a new troglophilic loach, Schistura densiclava (Teleostei: Nemacheilidae) from Meghalaya, northeast India.

Integrative taxonomy reveals a new troglophilic species of Schistura, from a cave-dwelling population inhabiting stream draining (Barak-Surma-Meghna drainage) through the Krem (=cave) Mawjymbuin in East Khasi Hills of Meghalaya. Morphologically, the new species is easily distinguished from its congeners in having a combination of characters, including a unique colour pattern in the form of 14-20 greyish black to faint black bars overimposed to a black midlateral stripe on a greyish brown to pale beige (yellowish green in life); pre-dorsal bars thin, numerous, wider than interspaces, weakly contrasted, sometimes broken and/or incomplete; bars posterior of anal-fin base numerous and variable, mostly broken or incomplete, located on lower flank, weakly contrasted; a complete lateral line; presence of an axillary pelvic lobe; an uninterrupted thick black stripe along the base of the dorsal fin; an incomplete black basicaudal bar, dissociated, occupying median one-third of caudal-fin base; conspicuous black botch on the procurrent rays of the upper lobe of the caudal fin; and a type of sexual dimorphism: males with slender body, bars mostly irregular on flanks and slightly puffy cheek with greater lateral head length; females with regular-shaped bars and swollen body. Analysis of the mitochondrial cytochrome c oxidase I (COI) gene sequence of the new species shows significant genetic divergence with p distances ranging 4.

Identification and characterisation of emerging fish pathogens Aeromonas veronii and Aeromonas hydrophila isolated from naturally infected Channa punctata.

Naturally infected Channa punctata exhibiting bacterial septicemic syndrome including ulcerations along with mortality records were collected from a fish farm in Assam during winter season (early November 2020 to early January 2021). The moribund fishes were subjected for bacterial isolation followed by identification of the bacteria. Two dominant emerging bacterial pathogens were identified as Aeromonas veronii (isolate ZooGURD-01) and Aeromonas hydrophila (isolate ZooGURD-05) by standard biochemical characterization and 16S rRNA and rpo B gene amplification.

Description of a new species of Mustura Kottelat (Teleostei: Nemacheilidae) from the Brahmaputra drainage, India.

Mustura subhashi, new species, is described from the Dikal River, a north bank tributary of the Brahmaputra drainage in Arunachal Pradesh. It is distinguished from all its congeners by having a colour pattern of 14-23 dark-greyish black to dark brown irregular bars on a greyish to pale beige body; pre-dorsal bars thin, numerous, wider than interspaces, weakly contrasted, uniting dorsally at lateral one-third or midway on flank to form thicker bars, coalescing further at lateral one-fifth and continuous on dorsum with contralateral bars; bars below dorsal fin exhibiting similar condition but slightly wider than pre-dorsal bars; post-dorsal bars thicker than anterior bars, wider than interspaces, sharply contrasted, rarely coalescing on flank; and a short bar along the caudal mid-line, rarely forming a blotch. Based on re-examination of the type specimens and additional materials, Mustura dikrongensis is confirmed as a species belonging to Mustura, and M.

Isolation and characterization of two virulent Aeromonads associated with haemorrhagic septicaemia and tail-rot disease in farmed climbing perch Anabas testudineus.

Diseased Anabas testudineus exhibiting signs of tail-rot and ulcerations on body were collected from a fish farm in Assam, India during the winter season (November 2018 to January 2019). Swabs from the infected body parts were streaked on sterilized nutrient agar. Two dominant bacterial colonies were obtained, which were then isolated and labelled as AM-31 and AM-05.

Schistura syngkai, a new fish species (Teleostei: Nemacheilidae) from Meghalaya, northeast India.

Schistura syngkai, a new stone loach, is described from the Twahdidoh Stream of Wahblei River (Surma-Meghna drainage) in Meghalaya, northeast India. It is unique among its Indian congeners in having a prominent dark-brown to blackish mid-lateral stripe about an eye diameter or more in width, overlain on 12-18 vertically-elongate black blotches on a golden-brown to amber body. Additionally, the species possesses an incomplete lateral line and a slightly emarginate caudal fin, and exhibits no apparent sexual dimorphism.

Psilorhynchus nahlongthai, a new fish species (Teleostei: Psilorhynchidae) from the Brahmaputra drainage, northeast India.

Psilorhynchus nahlongthai, a new psilorhynchid fish, is described from the Diyung River, a tributary to the Kopili River (itself a southern tributary of the Brahmaputra drainage) in Assam, northeast India. It is placed in the Psilorhynchus balitora species group and can be easily distinguished from all other members of this group by a combination of the following characters: dense and prominent tuberculation on the head region; thick and long pre- and post-epiphyseal fontanelles on the neurocranium; 9 + 8 caudal-fin rays; and 34 (24 + 10) vertebrae. Genetic divergence between P.

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 cavernicolous fish (Teleostei: Nemacheilidae) from Meghalaya, Northeast India.

Schistura larketensis, a new species of cavernicolous loach, is described from Khung, a limestone cave in Meghalaya, India. The species differs from Schistura papulifera, its only troglomorphic congener from northeast India, in having a smooth ventral surface of the head, the presence of a small cylindrical axillary pelvic lobe, and the presence of three pores in the supratemporal canal of the cephalic lateral-line system. Apart from these differences, the species can be immediately distinguished from all other species of Schistura from the Brahmaputra River and neighboring basins by the complete absence (or only vestigial presence) of eyes.