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

In the present study, amylase activity existing in the gut of different spe cies of sparid fish was measured and characterized. The study was conducted on five species of Mediterranean sparids, (F. Sparidae), some of which coe xist in the same coastal waters; Pagrus pagrus, Pagellus erytrhinus, P. bog araveo, Boops boops and Diplodus annularis. Main differences were found in the optimal pH for amylase activity as well as in sensitivity to temperatur e, with resistance to heating very low in B. boops and very high in D. annu laris. PAGE zymograms revealed the presence of two isoforms in all the spec ies, while the analysis of extracts using IEF showed a range from one to th ree 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 diversi fied amylase equipment. (C) 2001 Elsevier Science B.V. All rights reserved.