碩士 / 國立東華大學 / 生物技術研究所 / 93 / Cobia (Rachycentron canadum), a tropical marine teleost and major cage-cultured fish in Taiwan, is high economy and grows rapidly up to 6-8 kg/year with feed conversion ratios of 1.3 to 1.6. This experiment was attempted to investigate the relationship between fishes in different feeding habits with their digestive enzymes activity. Four kinds of fish including cobia, grouper (Epinephelus coioides), tilapia (Oreochromis mossambicus) and grass carp (Ctenopharyngodon idellus) stand for carnivorous, omnivorous, and herbivorous were chosen. The gastrointestinal track was dissected and made histological section to analyze the structure difference of stomach, pancreas and intestine among various species and further detect the pepsin, trypsin, chymotrypsin, ?amylase, aminopeptidase N and alkaline phosphotase activities and protein levels. The results showed that the stomachs of cobia and grouper have thick muscle layer and full of connective tissue (lamina) between two muscle layers. The intestine of cobia contains thick muscle and cavie instinct with piles. In the activity of digestive enzymes, cobia has the highest aminopeptidase N activity and the lowest trypsin and amylase activities among four species. The activities of pepsin and chymotrypsin in cobia are close to the grouper but higher than those of tilapia and grass crap. The activity of alkaline phosphatase in cobia is a little higher than grass crap and. Western blot data revealed that cobia has the highest pepsin protein expression. The protein level of trypsin in the pancreas of cobia is lower than that of grouper and tilapia. And the protein level of chymotrypsin among four species is similar. The cobia has higher pepsin and aminopepetidase N activities and the better ability of digestion and absorption in amino acid. Taken together, the higher growth rate may be correlated with the higher digestive enzymes activities and unique histological structure in cobia.
| Identifer | oai:union.ndltd.org:TW/093NDHU5108006 |
| Date | January 2005 |
| Creators | PI-HSIU LEE, 李璧秀 |
| Contributors | TZ Wu, 吳宗正 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 72 |
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