Effect of different dietary lipid sources on growth and gonad maturation of pre-adult female Cherax quadricarinatus (von Martens)

The effects of four dietary lipid sources (fish oil, peanut oil, soybean oil, pork lard) on growth and gonad maturation of pre-adult female red claw crayfish, Cherax quadricarinatus, were evaluated. Performance was evaluated by weight gain, specific growth rate (SGR), survival, feed conversion ratio (FCR), gonadosomatic index (GSI), fatty acid composition, and vitellogenin (vg) gene expression. The proportion of saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA), and poly-unsaturated fatty acids (PUFA) in hepatopancreas varied as a result of lipid source, while differences in muscle were limited to MUFA levels. Vg expression and growth, but not GSI, differed significantly, with peak expression and optimal growth observed in red claws receiving the soybean oil diet. Conversely, diets high in EPA (20:5n3) and DHA (22:6n3) produced suboptimal results, suggesting that the importance of maturation diets with high EPA and DHA content may be exaggerated. As the dietary lipid requirements of growing and reproductively active red claw crayfish were satisfied by a plant oil that contained high levels of 18-carbon unsaturated fatty acids, soybean oil may be an economic alternative to the expensive lipid-fortified feed currently utilized by the aquaculture industry.