Experiments on the Rearing of Rainbow Trout Oncorhynchus mykiss Walbaum in Kashmir

Rainbow trout is the native of rivers and lakes in the western half of North America. However, it has been transplanted across the world including Kashmir, India. Experiments conducted to study the rearing success of the fish at Dachigam Trout Fish Farm, Laribal, Kashmir, India during 2004-07 revealed that the fish attained tablesize (250 g) within 24 months. Fish were fed with formulated feed (having 40% protein content) at the rate of 4% of body weight daily in split doses. Early stages of the fish (up to advanced fry) were fed with higher protein content feed (48%) at the rate of 8% of body weight. Eggs were obtained by stripping (dry) and incubated in spring water. The eyed ova stage was reached within 14-20 days of stripping. The hatchlings appeared after another 10-15 days and these accepted artificial feed within another 14-20 days. The fish were reared up to advanced fry stage in spring water and the latter stages in stream water. The spring water at Dachigam showed a temperature range of 10.6-13.8°C, pH of 7.0-8.0, dissolved oxygen of 7.0-10.2 mg/L and free carbon dioxide of 0.6-1.7 mg/L, whereas the stream water showed a temperature range of 5.5-15.6°C, pH of 7.2-8.0, dissolved oxygen of 7.7-11.9mg/L and free carbon dioxide of 0.7-1.6mg/L. The saleable table sized trout showed feed conversion ratio (FCR) of 1.45 to 1.80. Males attained full maturity after 2 years, while females after 3 years.