Effects of starvation periods on total lipit and fatty acid composition of green tiger shrimp (Penaeus semisulcatus)

In this study, the effects of short (1 week) and long (3 weeks) starvation periods and re-feeding on muscle total lipid and fatty acids (FA) of the green tiger shrimp Penaeus semisulcatus (9.27±1.52 g) were investigated for 6 weeks. In the experiment; the 1st Group of shrimps were fed continuously (control), while the 2nd Group fed 3 weeks and fasted 1 week then re-fed for another 2 weeks, and the 3rd Group fed 3 weeks then starved for another 3 weeks. The experiment was performed in plastic containers (50x80x50 cm) in triplicates for each group, and each tank recived14 shrimps randomly. The shrimps were fed a shrimp diet consisting of 40% protein and 7% lipid three times daily during feeding periods. Short (1 week) and long (3 weeks) starvations resulted in 17.24% and 40.38% losses in the shrimp muscle total lipid content compared to that of the control group (P<0.05). Following the short starvation period, re-feeding for 2 weeks increased the muscle total lipid by 10.44% (P>0.05). Our results have demonstrated that, in general, while saturated (SFA) and mono-unsaturated (MUFA) FA?s were conserved in the muscle tissue, polyunsaturated (PUFA) FA?s were elevated during the short starvation period (P<0.05). The level of n-3 and n-6 series as well as 18:00 and 18:2n-6 rose, but 24:0, 22:2n-6 and 20:5n-3 were catabolised significantly during this period (P<0.05). Except MUFA?s, generally the levels of SFA, PUFA and n-3 FA?s were found to increase during the long starvation period (P<0.05). The highest catabolised FA was 18:1n-7 of the MUFA?s at this time. Significant fluctuations of the level of 24:0 during either starvation or feeding imply that this FA might be playing an important role in the energy requirement. The muscle MUFA, PUFA, n-3 and n-6 FA?s showed some sharp declines during the re-feeding period. The current results demonstrate that lipids and some FA?s are effectively catabolised as energy source during starvation in P. semisulcatus and that, despite hunger, the PUFA?s and HUFA?s, which play important roles in the structure of membranes, appear to be selectively retained or even elevated in the muscle tissue of this species.Key Words: Penaeus semisulcatus, Starvation, Re-feeding, Lipid, Fatty Acids