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Journal of Marine Biology
Volume 2014, Article ID 436789, 12 pages
Research Article

Development of Enzymes and In Vitro Digestibility during Metamorphosis and Molting of Blue Swimming Crab (Portunus pelagicus)

1Department of Aquatic Science, Faculty of Science, Burapha University, Bangsaen, Chonburi 20131, Thailand
2Biochemical Research Unit for Feed Utilization Assessment, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
3Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
4Department of Zoology, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
5Institute of Marine Research, Ecosystem Processes Research Group, Matre Research Station, 5984 Matredal, Norway

Received 29 May 2014; Accepted 14 September 2014; Published 8 October 2014

Academic Editor: Robert A. Patzner

Copyright © 2014 Phanu Chamchuen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The work focuses on development of digestive enzymes (amylase, total protease, trypsin, and chymotrypsin) and activity ratio of trypsin to chymotrypsin (T/C ratio) for digestive efficiency and growth, in blue swimming crab (Portunus pelagicus) during metamorphosis and molting. Specific activities of all enzyme parameters studied were associated with growth during metamorphosis, while only those of trypsin and T/C ratio were associated during molting cycle where trypsin and chymotrypsin specific activities associated with consumption rate with especially high levels during late intermolt and early premolt stages. About 50% increased weight gain was observed with at least double increased T/C ratio at the end of molting period, compared to the stages prior to molting. Growth of carapace would be more significant after finishing molting. Carapace width gain and T/C ratio were highest at the first crab stage. Studies of in vitro protein digestibility of different feed raw materials indicated that Artemia, Rotifer, and Moina are the best for larval stages. Otherwise, the use of shrimp feed and Artemia flake could be the alternatives. Incorporating of cassava meal into the feed formula for early adult stage (juvenile) could be an advantage. The proteins from animals are more beneficial for adult crab culture than the proteins from plants and bacteria. The digestible quality of dietary protein is very important during larval stages, while the protein level of diet is more important during adult stages with fully developed digestive enzymes.