The current results showed that diets with high energy diets (IV and V) negatively affected
gonad developments and weight gain of the Sharptooth catfish. Males and females fed diets
I, II, and III were classified as mature and were larger than fish fed on diets IV and V. The
intermediate energy level (12.73 MJ DE/kg diet—diet III) provided the best ovary and
testicular weights, GSI, and final weight gain as compared to others. When dietary energy
level increased (more than 12.73 MJ DE/kg or 8.5% soy-acid oil), poor gonad development
and growth were observed in both sexes of Sharptooth catfish. Similar results were
reported in studies with chicken broilers by Sevgican et al. (1986), and later in rainbow
trout diets by Canyurt et al. (1991). In both studies, a supplementary lipid level of
approximately 8.0% improved growth parameters. In contrast, the growth of hybrid tilapia
fry fed a diet with supplementary soy-acid oil was only slightly affected (Genc et al. 2005