Changes in lipid and protein during starvation and the moulting cycle in the tiger prawn, Penaeus esculentus Haswell

Abstract

Tiger prawns, Penaeus esculentus Haswell (mean wt 20.8 ± 0.3 g, range 13.9–27.7 g) contained 1–2% extractable lipid, 13% protein (biuret method) and 71–74% water (wet wt). In 21 days, the weight of fed prawns increased by 3% and that of starved prawns decreased by 4.4%. Protein was the major energy source during 14 days of starvation, with a loss of 550 mg of total protein compared with a loss of 84 mg of total lipid. The absolute amount of water present remained constant. Of three different tissue compartments, abdomen, cephalothorax, and digestive gland, the abdomen contributed the most protein (330 mg) and lipid (35 mg) during 14 days of starvation. Digestive gland, although containing the largest percentage wet wt of lipid, accounted for only 8.3% of the total lipid in the prawn, and contributed only 18 mg of lipid in 14 days of starvation. Lipid concentration in the digestive gland increased during early premoult (stage D 4) and dropped in late premoult (stage D 4). Resting oxygen consumption rate remained constant at ≈0.1 ml · g −1 · h −1 at 25°C during 21 days of starvation.