Scaly Osman

There are a number of moderate sized native demersal fish taxa that are found in the Indus River system including: the 70 cm scaly osman (Diptychus maculatus). Major tributaries of the Indus rise in the Himalayan Mountains and the Hindu Kush; these influent rivers include the Chenab, Jhelum, Ravi and Sutlej. The Indus mainstem rises on the Tibetan Plateau and flows generally westward. The Green Revolution has exacerbated water pollution by considerable additions of nitrate to promote crop growth. Other aggravating factors have included increasing amounts of herbicides and pesticides, as pressures to increase crop production expand. Flow of the perennial Indus is dominated by: (a) meltwaters from the Tibetan icefield, the third largest ice sheet formation in the world; (b) snowfall and snowmelt from higher elevation of the watershed; and (c) episodic monsoonal rains that lead to periodic flooding in the basin. Other large demersal fish associates in the Indus Basin are the 30 cm reba (Bangana ariza), the 30 cm Indus snowtrout (Ptychobarbus conirostris), the 30 cm Kunar snowtrout (Schizothorax labiatus), the 35 cm false osman (Schizopygopsis stoliczkai), the 47 cm Chirruh snowtrout (Schizothorax esocinus), and the 40 cm Sattar snowtrout (Schizopyge curvifrons).