A study on the enzyme activity of chitinase in farmed fish supplied with food where fishmeal was partially substituted with insect meal

The use of insect meal, rich in protein, is considered as a new alternative source of protein to the diet of farmed fish. However serious problems have been reported in fish growth rate when fish meal was substituted by insect meal at a percentage higher than 25%. The presence of insect’s body chitin was suggested as a reason for the observed lower growth rate. In our present work we investigated the effect of partially substituted fish meal by insect meal on the enzyme of chitinase in cultured gilthead seabream and rainbow trout. We also investigated the possibility of chitin from various sources being a limiting factor for food availability in alternatively fed cultured fish. For this reason we studied the effect of various chitins deriving from different organisms upon the activity of chitinase. Significant differences were noticed in both, the effect of the diet and the chitin source upon the kinetics of the enzyme activity.