The effect of water temperature on fatty acid content of the green tiger shrimp (Penaeus semisulcatus) under culture conditions

Response of proximate and fatty acid composition of muscle and hepatopancreas tissue contents of the green tiger shrimp (Penaeus semisulcatus) juveniles overwintered for 8-weeks at 11-16C and then refed fully at optimal conditions at 28C and 39 ppt for a further 2-weeks (recovery period) was examined in this study. Our results showed that P. semisulcatus did not appear to catabolise either proteins or lipids during the overwintering period, as the feeding was not ceasied completely. In general, saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA), and partially n-6 PUFA (poly-unsaturated fatty acids) declined, on the contrary, the levels of n-3 PUFA significantly rose in the abdominal muscle and hepatopacreas tissues during the cold exposure. The shrimps tended to metabolize especially SFA and, to a lesser degree, MUFA under thermal stress and restricted food consumption to meet their energy requirements (P<0.01). The level of n-3 PUFA, playing important roles in the tissue cell membrane stuctures, were amplified during the overwintering stress, but once the stressor is lifted, these fatty acids were no longer required to be conserved in the tissues. Inclusion of the overwintering strategy, as proposed in this study, might generate additional benefit in terms of a heathier food supply for human nutrition, as shrimps can be enriched for n-3 LC-PUFA, by simply keeping them under cold temperature (10-15C) for a certain period with minimal cost of feeding.