Responses of juvenile mud crab (Scylla serrata) to different oil sources and different levels of n-3 or n-6 polyunsaturated fatty acids

• Main Authors: Lin, Yea-Jen, 林雅真
• Other Authors: Shyn-Shin Sheen
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/34277339521722223425

碩士 === 國立海洋大學 === 水產養殖學系 === 84 === This study was conducted to investigate the effects of diets with different sources of lipid and different quantity of polyunsaturated fatty acids (PUFA) or highly unsaturated fatty acids (HUFA) on the growth and survival of juvenile crabs. In Experiment 1, juvenile crabs were fed with diets supplemented with 4 % cod liver oil, corn oil, olive oil, soybean oil and sesame oil for 10 weeks. The results showed that juvenile crabs fed with 4 % cod liver oil had the best growth. Juvenile crabs fed with diets containing corn oil, olive oil, soybean oil and sesame oil showed no significant differences. Juvenile crabs fed diets containing cod liver oil had high level of EPA and DHA of body tissue of juvenile crabs. These results showed that the fatty acid composition of tissue of crabs was obviously reflected from fatty acid composition of diet. Weight gain and survival responses and analyses of fatty acid composition of tissue were used to investigate the nutritional value of C18 polyunsaturated fatty acids (PUFA) provided to juvenile crabs in a purified diet. There were seven isonitrogenous and isoenergetic diets containing pure triglycerides of 0.2, 0.4 and 0.6﹪18:3n-3 (trilinolenin) and 18:2n-6 (trilinolein) and 0.2 ﹪22:6n-3 (tridocosahexaenoin) as control diet for experiment 2 . All diets were formulated to contain a total of 4﹪lipid and were fed to juvenile crabs for 12 weeks. The results showed that juvenile crabs fed diets containing 0.2﹪tridocosahexaenoin showed better growth than those fed diets containing trilinolenin and trilinolein. Diets containing high proportion of trilinolein or trilinolenin could not improve the growth of juvenile crabs. The high level of 18:2n-6 and 18:3n-3 in the polar and neutral lipids of tissue of juvenile crabs was found that crabs were fed diets containing trilinolein or trilinolenin. Crab fed diet containing 0.2 % tridocosahexaenoin had high level of EPA and DHA in the polar lipid of crab tissue. Weight gain and survival responses and analyses of fatty acid composition of tissue were used to investigate the nutritional value of C≧20 highly unsaturated fatty acids (HUFA) provided to juvenile crabs in a purified diet. There were isonitrogenous and isoenergetic diets containing pure triglycerides of 0.2, 0.4 and 0.6﹪20:4n-6 (triarachidonin) and 22:6n-3 (tridocosahexaenoin). Reference diet was included cod liver oil as the lipid source. All diets were formulated to contain a total of 4﹪lipid. A diets containing only saturated (14:0, 16:0, and 18:0) and monounsaturated (16:1n-7 and 18:1n-9) fatty acids as lipid sources, in proportions similar to that found in a 2:1 cod liver oil/corn oil mixture, served as a conditioning and control diets for experiment {= 3 \* ROMAN|III}. At the termination of the feeding trials, that juvenile crabs fed diets containing 0.4 % tridocosahexaenoin and 4 % cod liver oil had the best growth. The control group (diet included without PUFA and HUFA) had the lowest growth and survival. Crab fed diets containing 0.6 % triarachidonin and control group had high mortality. Crab fed diets containing triarachidonin (20:4n-6) and tridocosahexaenoin (22:6n-3) had high level of 20:4n-6 and 22:6n-3 in the tissue. However, crab fed diets containing tridocosahexaenoin (22:6n-3) had high level of EPA and DHA in the polar lipid of crab tissue.