Schizothorax plagiostomus

Schizothorax plagiostomus is a species of ray-finned fish in the genus Schizothorax. Schizothorax plagiostomus locally known as khont has an elongated sub cylindrical body with short, blunt and slightly prognathous upper jaw. Ventral surface of head and anterior part of body flattish, short, somewhat cone shaped and blunt. Snout usually smooth covered with warys in male. Interorbital space broad and flat. Mouth inferior, wide and slightly arched; lips fleshy and continuous, marginally sharply attenuated, lower lip papillae and reflected from jaw, margin of lower lip sharp, covered with firm and hard horny cartilage; a strip of papillae labial plate at chin present. Barbless two pairs. Pharyngeal teeth in three rows. Dorsal fin inserted about opposite to pelvic fins, its last undivided ray osseous, strong and serrated posterior, short than head. Caudal fin deeply emarginated. Scales very small and elliptical; lipids irregular.

Geographically S. plagiostomus spread in different rivers, and tributaries throughout Himalaya extending to confines of China, Afghanistan, Pakistan, Turkistan, Nepal, Ladkah, Tibet, Bhutan and north-eastern India (Day, 1958). In India, S. plagiostomus is the most important food fish of the Himalayan region, including Kashmir, Himachal Pradesh, Uttarakhand, the Uttar Pradesh foothills and Assam (Day, 1958). It also plays an important role in commercial fish production (Bahuguna, 2002).

According to Raizada (1985) S. plagiostomus weighs up to 2.5 kg and reaches 60 cm in length. It is sexually mature at 18–24 cm length and spawns in natural and artificial environments in two seasons, September–October and March–April. It spawns naturally in clear water on a gravelly or fine pebbled bed at 10–30 cm depth. Water current of 2.8–4 m/s, pH 7.5, dissolved oxygen concentrations Of 10–15 mg/l and gravel size of 50–60 mm are the optimum conditions for spawning.