Glyptothorax siangensis, a New Species of Catfish (Sisoridae) from the Brahmaputra River Drainage, Arunachal Pradesh, India

Glyptothorax siangensis, new species, is described from the Siang River in Arunachal Pradesh, India. The new species can be distinguished from its congeners from the Ganga-Brahmaputra drainage and its neighbouring drainages by the following combination of characters: a thoracic adhesive apparatus with skin ridges present over almost the entire apparatus, including the sword-shaped median depression, which is narrowly opened posteriorly; an elongated dorsal spine distinctly greater than body depth at its origin, posteriorly serrated with 11–17 serrae; nuchal plate saddle-like with W-shaped extensions; shallow body depth; long nasal barbel, almost reaching the anterior margin of eye; a complete longitudinal black band across the distal half of dorsal-fin; and tips of neural spines extension visible as a row of ridges between dorsal-fin base and origin of procurrent rays of caudal-fin. This is the nineteenth species of Glyptothorax known from the Ganga-Brahmaputra drainage.