a r t i c l e i n f o Recently, several groups of researchers reported that besides serine proteinases, other classes of proteinases may be involved in crustacean's food protein digestion, including cysteine and aspartic proteinases. In this paper, a comparative study of the class and type of digestive proteinases of whiteleg shrimp Penaeus vannamei, blue shrimp Penaeus stylirostris, and yellow...