The effect of the substitution of fishmeal with mealworm (Tenebrio molitor) on the survival, growth and quality of the European seabass (Dicentrarchus labrax) reared in Morocco

Insects are considered an alternative and sustainable source of protein in aquaculture diets. Hence, this work aimed to study the nutritional value of the larvae meal of Tenebrio molitor (TM) and evaluate the effect of its incorporation by partially substituting fishmeal in diets of seabass. For this purpose, four feeds (TM0, TM17, TM34, and TM50) with 0%, 17%, 34%, and 50% replacement of fishmeal, respectively were formulated, prepared, and tested on 280 fish with an initial average weight of 42.65 ± 0.81g. These fish were randomly divided into four feed groups in duplicate. Each group consisted of two tanks, each of which contained 35 fish individuals. These fish were hand-fed until satiation with one of the experimental diets. The results obtained showed that substitution of 50% of fishmeal by the larvae meal of TM improves the zootechnical performances and has no negative effect either on the feed intake, or on the analytical composition of the fish, or the intestinal microflora. Histological sections of the liver and intestine showed that there were no specific changes neither in the vacuolation of liver lipid cells, nor in the distribution, the number of caliciform cells or the intestinal rods.