<Emphasis Type="Italic">Glyptothorax dikrongensis</Emphasis>, a new species of catfish (Teleostei: Sisoridae) from Arunachal Pradesh,northeastern India

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 pelvic-fin 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).