Аннотация:The growth responses of juvenile crayfish, Procambarus clarkii Girard, to diets based on common fresh feedstuffs available from agriculture and freshwater ecosystems were studied under controlled laboratory conditions. The dietary treatments were: fresh leaves and shoots of watercress, fresh potato tubers, fresh fish meat from mosquitofish, and all the possible combinations of those ingredients on alternate feeding days. After 22 days, the results showed a significantly higher growth rate (P= 0.05) in crayfish fed with mosquitofish meat. The differences were not significant between the other treatments, but those which included fish meat induced growth rates consistently higher than those based only on plant ingredients. This trend was maintained until the end of the experiment. These results suggest that a dietary supplement based on animal ingredients might significantly improve growth rate and yield, provided the economic feasibility of such a production process be confirmed in field trials. However, it was not clear whether this was because of protein, or lipid concentration and composition of mosquitofish meat. Further research must also clarify the role of vegetable ingredients in dietary composition, as well as the effect of microbial populations occurring during the decomposition of plant material on its nutritional properties for crayfish.
