Influence of Starvation and Eyestalk Ablation on the Biochemical Composition of Hepatopancreas during Ovarian Development of Penaeus monodon

Under the conditions of water temperature of 26.0 ± 1.0°C, pH = 7.8–5.2, and salinity of 28–30 ppt, the parent shrimp of Penaeus monodon (body weight of 128.71 ± 4.06 g/ind.) were subjected to starvation and eyestalk removal for 11 days. Four groups were set up: control group (CG), eyestalk removal group (RG), starvation group (SG), and starvation + eyestalk removal group (RSG). The changes in glucose, cholesterol, and triglyceride content in the hepatopancreas of the parent shrimp during ovarian development were measured using morphological anatomical weighing and enzymatic methods.The experimental results showed that during the breeding period, the content of glucose, cholesterol, and triglycerides in the hepatopancreas of parent shrimp showed a decreasing trend with the continuation of ripening promotion time. Among them, the parent shrimp in SG and RSG got the largest changes in glucose and triglyceride content in hepatopancreas, with glucose content decreasing from 140.22 ± 5.39 to 24.83 ± 2.48 g/kg and from 139.75 ± 8.11 to 26.87 ± 2.73 g/kg, respectively, and the content of triglycerides decreased from 16.21 ± 3.72 to 5.66 ± 0.44 g/kg and from 15.36 ± 2.54 to 6.40 ± 0.29 g/kg, respectively. The levels of cholesterol and triglycerides in hepatopancreas of RSG showed the greatest changes, decreasing from 82.71 ± 10.72 to 15.70 ± 1.38 g/kg, with a decrease of 81.02%. During the experiment, the levels of three biochemical reserves in RG remained lower than that of CG, and RSG remained lower than that of SG, while SG remained significantly lower than that of CG. The results suggests that during the breeding period, the absorption and accumulation of glucose, cholesterol, and triglycerides in hepatopancreas of parent shrimp are less than those in transfer. Eyestalk removing was able to promote the transfer of glucose, cholesterol, and triglycerides from the hepatopancreas of shrimp to the gonads through hemolymph, accelerating the efficiency of energy conversion. The biochemical reserve substances required for gonadal development mainly come from food, and hunger was not conducive to gonadal development.