Unlike endotherms, ectothermic species do not have the primary responses to infection which is a rapid increase in body temperature known as fever. Aquatic ectotherms modify body temperature by moving to warmer waters, this is a phenomenon known as ‘behavioural fever’. Behavioural fever is defined as an acute change in an organism’s thermal preference driven by pathogen recognition.
This study aimed to evaluate the effects of pond modification on water quality, growth performance, and hemato-biochemical profile, immune-oxidative status of Oreochromis niloticus fingerlings. Fish (0.5±0.189 g, 15000 fry/ fadan) were randomly distributed in duplicates into two experimental groups. The control group (CG), fish were reared in an earthen ponds without any modifications. The experimental group (GH), fish were reared in an earthen ponds with greenhouse (3 % of pond area) as a modifications. Greenhouse area represents 3% of the pond area; it consists of metal frame fastened at an edge of the pond by pillars and sealed with transparent UV stabilized low density polyethylene film (LDPE) of 250µm thickness.
The results revealed that fish reared in ponds modified with greenhouse effect showed an improvement in the growth performance, survival and feed utilisation efficiency (P<0.05) . However, there was no significant effect of pond modification on water quality parameters. Hemato-biochemical parameters were improved in GH group specially RBCs, WBCs, total protein and globulin. In the same context, the fish reared under greenhouse modification showed an improvement in antioxidant parameters (SOD and CAT) and immune response (phagocytic activity, phagocytic index and lysozyme activity) compared to CG (P<0.05) .
In conclusion, pond modification improved growth performance, water quality, hemato-biochemical profile, immune-oxidative status of Nile tilapia.