Digestive enzyme activity during initial ontogeny and after feeding diets with different protein sources in zebra cichlid ; Archocentrus nigrofasciatus

This study aims to describe changes in the activity of digestive enzymes of the zebra cichlid ; Archocentrus nigrofasciatus ; from hatching until 30 d after hatch (d.a.h.) ; and to evaluate the effects of feeding diets with different levels of fishmeal (FM) substitution with alternative nonanimal protein sources from 30 d.a.h. up to the age of 60 d.a.h. Results indicated that the developmental patterns of digestive enzymes from the exocrine pancreas and intestine are similar to those of other phylogenetically close cichlids ; although they seemed to develop faster than other species as indicated by the peaks in enzyme activity ; which were detected at younger stages of development. The 100% FM replacement with different alternative nonanimal protein sources had a negative impact on the growth performance of A. nigrofasciatus juveniles ; whereas fish fed the diet with a 50% FM replacement showed similar results to those fed the 100% FM diet. Fish showing the lowest growth rate had also the lowest enzyme activity ; especially in relation to the intestinal brush border enzymes. This study assesses the digestive capabilities and nutritional condition of the zebra cichlid fish and provides knowledge on the potential for FM substitution in their feeds.