Manuel Díaz

Characterization of α-amylase activity in five species of Mediterranean sparid fishes (Sparidae, Teleostei)

Abstract In the present study, amylase activity existing in the gut of different species of sparid fish was measured and characterized. The study was conducted on five species of Mediterranean sparids, (F. Sparidae), some of which coexist in the same coastal waters; Pagrus pagrus , Pagellus erytrhinus , P. bogaraveo , Boops boops and Diplodus annularis . Main differences were found in the optimal pH for amylase activity as well as in sensitivity to temperature, with resistance to heating very low in B. boops and very high in D. annularis . PAGE zymograms revealed the presence of two isoforms in all the species, while the analysis of extracts using IEF showed a range from one to three active bands. It is suggested that differences in amylase activity are related to variations in feeding habits of the studied fish, and could also represent an ecological advantage for those species showing a more diversified amylase equipment.