Trace and heavy metal content in diets and their effect on the growth and survival of Siamese fighting fish, Betta splendens

Three hundred one month old Betta splendens fry (mean weight 0.141g±0.02) were equally distributed in five groups, each with three replicates in 35-L glass aquaria. The five groups were; control (C)-Tubifex (live food); T₁-formulated feed (FF); T₂-FF+0.01% vitamin E; T₃-FF+1% eicosapentaenoic acid (EFA)+docosahexaenoic acid (DHA) and T₄-FF+0.01% vitamin E+1% EPA+DHA and the experiment continued for 126 days. Highest (P<0.05) average body weight and survival was observed in C and T₂ group, respectively. Highest zinc (Zn) and manganese (Mn) concentration in diets and muscle were recorded in C and T₁ groups, respectively. Control group recorded highest selenium (Se) in diet and muscle. Highest copper (Cu) in diet and in fish muscle was measured in T₁ and C group, respectively. Highest iron (Fe) content in diet and muscle was recorded in C and T₄ group, respectively. Highest (P<0.05) cobalt (Co) in diet and fish muscle was found in C group. Highest cadmium (Cd) in fish muscle was recorded in T₄ group but did not differ from T₃ group. Highest liver weight was measured in C group. So, observing all factors, present study concludes that live food exhibited the best growth and diet added with vitamin E (T₂) showed the highest survival, compared to the diets enriched with EPA+DHA.