Abstract:
Blue swimming crab, Portunus pelagicus consumed variety kind of food as their diet.
The study shows that their dietary items are molluscs, crabs and seagrass, including
unidentified items that semi-digested. They are categorized as cannibalism because
they consumed other crabs where the parts of crab's appendages were found in their
foregut. They are omnivore group, as they eat other animal, they also consumed
plants. Amylase, protease, and trypsin were detected in all sample and stages, except
lipase, indicate that P. pelagicus readily digest dietary protein and carbohydrate at all
stages. The changes in enzyme activities between stages reflect the changes in natural
diet and feeding abilities. High proteolytic activity reflects a diet high in protein as
show by matured males (MA). Meanwhile, carbohydrase activity reflects a diet with
starch or cellulose that consumed by all stages especially matured males (MA),
females with ovarian stage two (S2) and immature males (IM). And the high lipase
activity reflects a diet high in fat as shows by female with ovarian stage four (S4).
