Induced breeding of snowtrout (Schizothorax richardsonii -Gray), from Garhwal Himalaya (Uttarakhand, India) by pituitary gland extract

Abstract

Comparative breeding experiments were done in Schizothorax richardsonii by using pituitary gland extract (PGE) and stripping technique. Experiments were conducted for two successive years. PGE dose administered was 5mg/kg body weight to male fishes and 7 mg/kg to female fishes. Each dose was administered as two split doses 4 hours apart. For induced breeding, fecundity ranged from 5,200 to 13,542 eggs per female. In 15 sets of induced breeding experiments performed over two years, using PGE extract, fertilization success ranged from 78±1.98% to 76.7±2.18% and hatching success ranged from to 63.3±%3.05to 63.9±1.81%. Stripping experiments yielded similar results with their fertilization ranging from 67.7±3.48% to 64.4±2.67% and hatching ranging from 58.9±3.47% to 57.26±2.8%. Our results conclude that induced breeding is better than stripping and can be used effectively to breed Schizothorax richardsonii.

Intra‐annual changes in reproductive indices of male and female Himalayan snow trout,Schizothorax richardsonii(Gray, 1832)

“…Although, in the recent past, some success has been achieved in artificial propagation of snow trout S. richardsonii with wild collected brooders (stripping in case of ready to ooze individuals as well as induced spawning with ovaprim (GnRH) in case of individuals not showing positive response to stripping), the culture of schizothoracines is still in its experimental stage (Agarwal, Thapliyal, & Raghuvanshi, 2007; Singh, 2015). Earlier attempts to induce spawning through hypophysation have failed or did not attain satisfactory results (Raina, Vass, Sunder, Moza, & Langer, 1985; Seghal, 1999), and Thapliyal, Bahuguna, Chandra, and Thapliyal (2012) reported the potential of induced breeding of snow trout by pituitary gland extract (with 76%–78% fertilization rate and 63% hatching rate). Despite these advancements, the domestication and captive breeding of snow trout are still at its infancy and most of the breeding programmes still depend on wild collected brooders.…”