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

Abstract

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.

The complete mitochondrial genome of Exostoma gaoligongense (Siluriformes: Sisoridae) and its phylogenetic analysis within glyptosternine catfishes

“…The genus Exostoma Blyth 1860, belonging to the glyptosternine catfishes within Sisoridae, is characterized by having a strongly depressed body profiles and horizontally enlarged paired fins modified for adhesion, continuous post-labial groove, homodont dentition consisting of distally flattened oar-shaped teeth and two narrowly-separated patches on the upper jaw and two well-separated patches on the lower jaw (Thomson and Page 2006;Darshan et al 2019). Species of genus Exostoma primarily inhabit the bottom of the rocks in the swift-flowing mountain streams or rivers from the Yarlung Tsangpo-Brahmaputra River drainage eastwards to the Lancang-Mekong River drainage (Gong et al 2018).…”

Comparative Mitogenomics of Two Sympatric Catfishes of Exostoma (Siluriformes: Sisoridae) from the Lower Yarlung Tsangpo River and Its Application for Phylogenetic Consideration

“…The subfamily Glyptosternae is a specialized group of catfishes belonging to the order Siluriformes and family Sisoridae, and is found primarily in the Tibetan Plateau and adjacent drainage basins. The genus Exostoma Blyth 1860—a clade of glyptosternine catfishes—can be distinguished by their having a continuous post-labial groove, flattened ventral surface of the body with horizontally patulous paired fins specified for adhesion, and distally flattened oar-shaped homodont dentition in two separated patches on both the upper and lower jaws [ 5 , 6 ]. Fishes of this genus generally dwell beneath the rocks in torrential streams and rivers, with a distribution range across from the Yarlung Tsangpo–Brahmaputra River drainage eastwards to the Chao Phraya River drainage in northwestern Thailand [ 7 ].…”