The present study focused on the effect of crowding and crowding-with-feed restriction in Labeo rohita fingerlings of an average weight of 8.5 ± 0.5 g. The experiment was conducted with 180 fingerlings distributed randomly in four distinct groups with each group in triplicate viz, Control (C) (stocking density at 10 fish/75 L with satiation feeding), T1 (stocking density at 10 fish/ 75 L with restricted feeding at 1% of body weight), T2 (stocking density at 20 fish / 75 L with satiation feeding) and T3 (stocking density at 20 fish / 75 L with restricted feeding at 1% body weight) for 48 h. Serum samples were collected at regular intervals of 3, 9, 24 and 48h. The serum total antioxidant status of the control group was significantly higher (p<0.05) than the stressed groups from 9 h onwards while the catalase and glutathione peroxidase showed an increasing trend after 24 h. There was no significant effect of stress on serum triglyceride profile except for the triglyceride levels at 3 h of stress exposure. The serum antioxidants started varying only after 9 h of stress exposure. Blood glucose levels varied only after 9 h of stress exposure and haemoglobin content were higher in feed restricted and crowding with feed-restricted groups compared to control. Blood and serum parameters are often used as an indicator of stress in fish, and the variation in serum triglyceride profile and the activity of enzymatic antioxidants indicated that crowding as well as crowding-with-feed restriction are acute stressors in aquaculture farms.
Shamna et al. (Fri,) studied this question.