Journal of Fishery Sciences of China (中国水产科学) 2013/20:6 PP.1175-1181
We used 1-year-old juvenile Chinese mitten crab Eriocheir sinensis with the shell width at 1540 mm, temporally reared them in the aquarium of 75 cm×50 cm×45 cm, 24 h aerating and natural light. We changed the water at 1/3 each day and used potato and small fish as the feed for the crab. One week later we began the experiment. According to the reference reported, we divided the period of molting cycle of the E. sinensis into 5 stages as stage C (intermolting) , stages D0, D1, and D3–4 (premolt), and stage A-B(postmolt). We evaluated the changes in the hepatopancreas cell type composition during the molting cycle using cellular and histological methods. R (resorptive) cells were the most abundant cell type throughout the molting cycle, except during the postmolt A-B stage. The number of B (blisterlike) cells increased significantly (P<0.05) between intermolt C stage and premolt D0 stage, gradually decreased thereafter until the later premolt D3–4 stage, then increased significantly during the postmolt A-B stage (P<0.05). The number of F (fibrillar) and E (embryonic) cells generally did not change significantly (P>0.05), but did increase significantly during the premolt D1 and D0 stages (P<0.05). The effect of fasting on the hepatopancreas cell type differed among the molt stages. During the D0 stage, the number of B and E cells decreased significantly (P<0.05), whereas the number of F cells increased significantly (P<0.05), in fasting animals relative to fed (unfasted) animals. The number of R cells was not affected (P>0.05) by fasting. During the D1 stage, fasting had no effect (P>0.05) on the numbers of all cell types. Our results suggest that hepatopancreas cell type composition of E. sinensis changes with molt stage. The purpose of this study is to understand the basic biologic change during the molt of crustacean and to provide a fundamental reference for the healthy aquaculture of this species.