ABSTRACT

Glyptosternines are highly specialized sisorid catfishes with greatly depressed body profiles; enlarged, horizontally extended paired fins, modified for adhesion, typically inhabiting torrential waters in rocky mountain streams and rivers. Their range of distribution extends from the upper reaches of the Amu Darya River drainage in Turkmenistan southwards and eastwards to Indochina and the Yangtze River (Changjiang) drainage of central China, and the Mekong and Salween drainages in northern and western Thailand (Vidthayanon et al. 2009; Ng & Vidthayanon 2014).

Physoschistura walongensis, new species, is described from the bank of the Lohit River (upper Brahmaputra River basin) in the eastern most part of the state Arunachal Pradesh at an altitude of 1096 m above sea level. The new species is distinguished from its congeners by the following combination of characters: an incomplete lateral line extending at least to the anal-fin origin and maximally to the tip of the adpressed anal fin, with 71-89 canal pores; a rounded suborbital flap, the posterior margin of which slightly exceeds the anterior orbital margin, occupying less orbital area; body with 11-18 irregular vertical bars on the flank, bars more irregular on the anterior portion of the body than on posterior; 1-4 bars bifurcate ventrally; 1-4 saddles along the ventrolateral side of the body; a moderately thick W-shaped basicaudal bar; a prominent axillary pelvic fin lobe; dark brown mottled markings on the head; and forked caudal fin with 9 upper + 8 lower branched rays.

Glyptothorax dikrongensis, a new species of sisorid catfish from the Dikrong River in northeastern India, is described. Glyptothorax dikrongensis can be differentiated from all congeners, except G. indicus, G. rugimentum and G. obliquimaculatus, by the presence of an unculiferous patch on the posterior region of the lower lip, in between the inner mandibular-barbel bases, and unculiferous striae of the thoracic adhesive apparatus extending anteriorly onto the gular region. Glyptothorax dikrongensis is distinguished from G. indicus by the following combination of characters: equal distance between the posterior end of the pectoral-fin base and the pelvicfin origin and between the pelvic-fin and the anal-fin origin (vs. distance between posterior end of pectoral-fin base and pelvic-fin origin greater than between pelvic-fin origin and anal-fin origin), and the pelvic-fin origin anterior to or almost at a vertical through the posterior end of the dorsal-fin base (vs. posterior to the dorsal-fin base). Glyptothorax dikrongensis is distinguished from G. rugimentum in lacking vertical bars on the body and caudal peduncle, and having a deeper caudal peduncle (8.4-9.2 vs. 6.1-7.6% SL) and a shorter dorsal-fin spine (10.1-11.1 vs. 15.2-18.6% SL). It is distinguished from G. obliquimaculatus in lacking dark, oblique blotches on the body, and in having a shorter dorsal-fin spine (10.1-11.1 vs. 13.4-16.4% SL).

This study describes Pseudolaguvia viriosa, a new miniature sisorid catfish from the Brahmaputra River drainage in Ar-unachal Pradesh, northeastern India. Pseudolaguvia viriosa can be distinguished from congeners in having a combinationof: eye diameter 10–15% HL, interorbital distance 35–38% HL, head width 21.5–23.5% SL, thoracic adhesive apparatusreaching beyond base of last pectoral-fin ray, pectoral spine length 26.9–32.9% SL, dorsal spine length 23.4–29.0% SL,dorsal spine with anterior edge smooth or with rugose surface only on distal third of spine, body depth at anus 16.9–19.0%SL, length of adipose-fin base 12.5–15.4% SL, caudal peduncle length 14.8–17.7% SL, caudal peduncle depth 7.4–9.8% SL, caudal-fin length 26.5–32.4% SL, 28–29 vertebrae, and one or more distinct pale bands encircling body.