Effect Of Stocking Density On Body Composition And Antioxidant System In Yellow Catfish (Pelteobagrus Fulvidraco)

This experiment was conducted to evaluate the combined effects of stocking density on body composition and antioxidant system in Pelteobagrus fulvidraco. Fishes were divided into two experimental groups:high stocking density (HSD; n=90) and low stocking density (LSD; n=15). After 60 days, fishes were weighed, tissues sampled and differences between the two groups analyzed statistically, with P<0.05 chosen as significant difference (SD) level. LSD group had a significantly higher total weight gain, but average daily gain, specific growth rate and condition factor were not significantly different. The composition of muscle tissue was SD for crude protein and fat, but not SD for moisture and ash. All four antioxidant parameters (glutathione, glutathione peroxidase, total anti-oxidative capability and catalase) studied from liver samples were SD. All three hormones, a stress hormone (cortisol) and two metabolism-regulating thyroid hormones (triiodothyronine and thyroxine), studied from blood samples were SD. Seven out of eight (glucose, albumin,total protein,blood urea nitrogen,total cholesterol, lactate dehydrogenase, alkaline phosphatase and triglycerides) biochemical parameters studied from blood samples were SD, withblood urea nitrogen as an exception. The results indicate that even though there are many observable negative impacts of high stocking density on physiology of the yellow catfish, relatively small difference in growth performance between the two groups suggests that high stocking densities might still be a viable alternative for the aquaculture of this species.