Evaluation of mealworms (Tenebrio molitor) meal as an alternative protein source for narrow-clawed crayfish (Pontastacus leptodactylus) juveniles

Abstract

An eighty-day feeding study was performed to investigate the effects of mealworm meal (Tenebrio molitor) on the growth, survival and moulting frequency of juvenile Narrow-clawed crayfish (Pontastacus leptodactylus). Three dietary treatment groups with triplicate were fed with a fish meal-based without MW (control diet: MW0), two diets with 50% (MW50) and 100% (Mw100) of fish meal substitution with MW respectively. P. leptodactylus juveniles (11.0 +/- 0.05 mm, mean +/- SE and 0.011 +/- 0.002 g, mean +/- SE) were randomly stocked into nine flow-through tanks with a density of 30 crayfish per tank and reared for 80 days. Crayfish fed with MW50 mealworm meal showed positive effects on weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER), apparent net protein utilization (ANPU), moulting frequency (MF) and feed conservation ratio (FCR), but lower survival rate (SR) as compared to the other diet groups. Protein and lipid contents of the whole body of the crayfish fed with replacement diet (MW50) were found to be higher than those of the other two diet groups (p<0.05). However, the MW100 diet slightly increased the moisture and ash contents of the crayfish. Our observation indicated that the addition of a 50% mealworm meal in the diet of P. leptodactylus juveniles improved the growth performance of the crayfish without causing any adverse effects. Therefore, T. molitor meal can be considered as an alternative animal source of protein for the narrow-clawed crayfish juveniles.