title: Partial characterization and ontogenetic development of pancreatic digestive enzymes in Japanese eel Anguilla japonica larvae.
abstract: The pancreatic digestive enzymes, trypsin, chymotrypsin, lipase and amylase were partially characterized, and changes in their activities were examined during the initial ontogeny of Japanese eel Anguilla japonica larvae from 5 to 34 days post-hatching (dph). The pH optima of the eel larval enzymes were narrower than those other fish species; trypsin activity was highest at pH 9, chymotrypsin and amylase activities were highest at pH 7 and 8, and lipase activity was highest at pH 8 and 9. In an analysis of thermal profiles, the larval pancreatic enzymes had a high optimal temperature and high thermal stability, which are typical of fish from the tropics. At 12 and 13 dph, lipase activity and gene expression levels of trypsin (-a and -b), lipase and amylase decreased markedly, suggesting a marked change in larval metabolism at that time. These data could be useful in the development of artificial larval diets in Japanese eel.
authors.affiliation: National Research Institute of Aquaculture, Fisheries Research Agency, 224-1, Hiruta, Tamaki, Mie 519-0423, Japan. kojim@affrc.go.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Murashita
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Furuita
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsunari
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Masahiko
authors.initials: M
authors.lastname: Awaji
authors.forename: Kazuharu
authors.initials: K
authors.lastname: Nomura
authors.forename: Jiro
authors.initials: J
authors.lastname: Nagao
authors.forename: Hideki
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000681:Amylases / Q000378:metabolism; D000811:Anguilla / Q000254:growth & development / Q000378:metabolism*; D000818:Animals; D002918:Chymotrypsin / Q000378:metabolism; D004063:Digestion; D029941:Fish Proteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007814:Larva / Q000201:enzymology; D008049:Lipase / Q000378:metabolism; D010179:Pancreas / Q000201:enzymology*; D013696:Temperature; D014357:Trypsin / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D008049:Lipase; D000681:Amylases; D002918:Chymotrypsin; D014357:Trypsin