Effect of stress conditions on condition factor and growth of farmed Rohu (Labeo rohita)
Muhammad Zubair Hussain and Syed Qaswar Ali Shah
To investigate the effects of stressors on condition factor and specific growth rate in farmed Labeo rohita, 60 fingerlings were subjected to experimentation in laboratory aquaria after being acclimatized. Specimens were divided into control, starvation stress and double stress (pH = 8 and starvation) groups with 20 individuals in each group. Total length (L) and total weight (W) of the fishes was measured after 12, 24, 36 and 48 days. Condition factor (K) was calculated by using formula, K = (W/L3) x 100. % Specific growth rate was calculated by using formula, %SGR = (log e W2 – log e W1/T) x 100; where, T = Duration of experiment. The data was subjected to one way ANOVA for comparison between and within groups. There was considerable decrease in condition factor, though statistically non-significant, in starvation and double stress groups compared to control group after 12 days; however, this decrease was significant (P<0.05) after 48 days. Within group comparison revealed no significant effect of stressors on condition factor. A considerable decline in growth rate/de-growth was recorded in all three groups, comparatively more in magnitude in stress groups compared to the control. Within group comparison revealed a significant effect (P<0.01) of stress in starvation group, but statistically no significant effect in double stress group. It is concluded that stress conditions affect growth of Labeo rohita at early stages.