Browsing Proceedings of the First International Conference on the Culture of Penaeid Prawns/Shrimps by Subject "fatty acids"

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    • Effect of dietary fatty acids on the fatty acid composition of Penaeus monodon juveniles 

      Catacutan, M.; Kanazawa, A. (Aquaculture Department, Southeast Asian Fisheries Development Center, 1985)
      Six purified diets containing either pollack liver oil or a combination of dietary fatty acids (18:1ω9, 18:3ω3, 20:5ω3) at 5% level and a control (no lipid) were assessed for their influence on the fatty acid composition of Penaeus monodon juveniles (0.2-0.5 g). After a 35-day feeding period, the fatty acid composition of the neutral lipid (NL) and polar lipid (PL) fractions of prawn total lipids was analyzed. All treatments showed that the prawn lipid contained high level of polyenoic acids (20:4ω6, 20:5ω3, 22:6ω3); likewise the sum of ω3 series fatty acids were high in the PL fraction. The component fatty acids of prawns showed a correlation with those of the diet. However, some dietary fatty acids were incorporated more into the NL fraction (18:1ω9, 20:5ω3) than in the PL fraction (20:4ω6). The ratios of 18:1ω9/22:6ω3 and (18:1ω9 + 20:1ω9)/(20:5ω3 + 22:6ω3) were found to be the lowest in the PL of the prawn pollack liver oil.

    • Effects of diet on reproductive performance of ablated Penaeus monodon broodstock 

      Millamena, O.M.; Pudadera, R.A.; Catucatan, M.R. (Aquaculture Department, Southeast Asian Fisheries Development Center, 1985)
      Four practical diets were compared for their effects upon ovarian maturation and spawning of ablated Penaeus monodon broodstock. Diets were formulated based upon the fatty acid profile of wild P. monodon. Diets 1 and 3 were cod liver oil-based while Diets 2 and 4 were soybean oil-based. Experimental treatments consisted of each of the formulated diets given in combination with natural food (squid, mussel, and annelids). An all-natural diet served as control. The fatty acid composition and total lipid content of the diets and of P. monodon fed with these diets were assessed. Reproductive performance was evaluated in terms of number of spawnings, fecundity, egg and nauplii production and hatching rate of eggs. Broodstock response was best in Diet 1 and comparable with the control, followed by Diets 3 and 4, and was poorest in Diet 2. Broodstock performance appeared to be related to the fatty acid pattern of the diet. All pelleted diets contained similar levels of total lipids. However, there were differences in amounts of important polyunsaturated fatty acids (PUFA): 20:4ω6 (arachidonic), 20:5ω3 (eicosapentaenoic) and 22:6ω3 (docosahexaenoic) acids. The fatty acid profiles of Diets 1 and 3 more closely resemble the profile of maturing ovaries of wild P. monodon; the PUFA content of these diets and ω3/ω6 ratios were higher compared to Diets 2 and 4. Diet 2, showing the poorest profile among the diets, was low in ω3/ω6 ratio and contained minimal levels of PUFA.

    • Lipids and essential fatty acids in the nutrition of Penaeus monodon larvae 

      Millamena, O.M.; Quinitio, E.T. (Aquaculture Department, Southeast Asian Fisheries Development Center, 1985)
      Total lipid levels and fatty acid distribution during larval development of Penaeus monodon were determined. Larvae were cultured utilizing standard rearing procedures and feeding schemes adopted by the Crustacean Hatchery of SEAFDEC Aquaculture Department in Tigbauan, Iloilo, Philippines. At each developmental stage (spawned egg, nauplius, protozoea, mysis, postlarva), samples were collected for biochemical analysis. Lipid content decreased with developmental stage (from egg to postlarva), indicating utilization of lipids as energy source during larval development and metamorphosis. The major fatty acids in the egg lipid were 16:0 (palmitic), 16:1 (palmitoleic), 18:0 (stearic), 18:1 (oleic), 18:3 (linolenic), 20:4 (arachidonic), 20:5 (eicosapentaenoic), and 22:6 (docosahexa-enoic acids. As the larvae developed, levels of 16:1 and 18:1 fatty acids decreased with a corresponding increase in polyunsaturated fatty acids (PUFA), particularly 20:5ω3 and 22:6ω3. These indicate the importance of PUFA as dietary components. Comparison was made between fatty acid changes during larval development and the fatty acid constituents of commonly used larval feeds (algae, rotifer, brine shrimp, egg yolk) for P. monodon. The algae and zooplankton were found to contain 20:5ω3, while egg yolk was high in total lipids but low in polyunsaturates. Most larval diets were deficient in 22:6ω3 fatty acid. Crustaceans have been shown to have a limited capacity to biosynthesize long-chain PUFA; these have to be provided in their diet. These essential fatty acids must be available in appropriate amounts to ensure successful larval development and survival.