Egg incubation and larval rearing of rainbow trout (Onchorhynchus mykiss) at higher thermal regime in mid hills

Abstract

Culture and hatchery management of rainbow trout is a temperature dependent activity. An attempt has made to observe the response of higher thermal regime of optimal range on incubation, growth and survival rate of eyed ova of this fish in coldwater condition. Incubation and larval rearing were observed at temperature range of 16-200C for 90 days at Bhimtal. 10000 eyed ova were used during the observation. Vigorous aeration and water flow at 1.5 LPM was maintained for the favorable environment. During the observation hatching was observed on 8d at hatching rate of 69%. Survival of larvae after 90 days of observation was recorded as 64%. The results showed a successful incubation and larval rearing at higher thermal regime, however, sufficient Dissolved Oxygen and water flow is required for getting desirable results in mid hills. The findings enable the feasibility of hatchery operation of this species even at higher thermal regime.