Respiratory Responses Of Indian Major Carp Catla Catla (Hamilton) During Thermal-Stress And Thermal-Adaptation

Abstract

The two vital respiratory parameters namely Oxygen consumption of the whole fish and the Opercular activity in the Indian Major Carp was investigated during thermal-stress and Thermal-adaptation. The Indian major carp Catla catla subjected to and Slow temperature change from 22 ⁰c to 32⁰c (heat-adaptation) and 32⁰c to 22 ⁰c (cold -adaptation) at the rate of 1⁰c ̷ 60 hours showed a gradual stepping-up of oxygen consumption and opercular activity in heat-adaptation and a stepping-down of oxygen consumption and opercular activity in the case of cold-adaptation and in both cases reached the control values within 35 days, where as Catla catla exposed abruptly to a temperature change from 22 ⁰c to 32⁰c (heat-stress) and 32⁰c to 22 ⁰c (cold -stress) at the rate of 1⁰c ̷ hour exhibited neither stepping-up nor stepping-down in oxygen consumption and opercular activity and they could not reach the control values within 35 days. Stress is a physiological load acted upon the fish, where as adaptation is a slow process of compensation without physiological load