Studies On Nutrient Accumulation And Energy Strategy Of The Eriocheir Sinensis Living After The Last Winter Before The First Molting In The Next Year

This research was mainly around the Chinese mitten crab(Eriocheir sinensis), which lived after the last winter and before the first molting in the second year. Different kinds of diets, including the corn, the crusion carp, the snail(Spiral lions), the sea-fish(Pneumatophorus japonicus), and the formulated diet, was used to feed different body-size crabs. The samples of different body-size crabs were collected at three certain time in turn: before feeding, after five-day’s feeding, and nearly before the first molting. The major biochemistry factors was determined, including the content of total lipid and crude protein in the hepatopancreas and muscle, and the energy densityof the whole individual. The composition of amino acid in the muscle was determined. During the long-time winter, with low temperature and without enough food, Chinese mitten crabs would rely on the consumption of the nutrition storing in the organization before the winter. This research aimed to study the nutrient accumulation and energy strategy of the crabs which survived from the frozen winter and were fed by different kinds of diets till their first molting. Mainly results were following: 1. Different kinds of diets significantly affected the composition of amino acid in the muscle(P<0.05). After five-day’s feeding, the essential amino acid and the total amino acid of the small size crabs fed with the crusion carp was significantly higher than those of the other four diets groups(P<0.05). There were nine kinds of essential amino acid, which was the most content, in the crusion carp group. The large body-size crabs fed with the corn was significantly higher than those of the other four diets groups(P<0.05). This result showed that the requirement of amino acid in the small body-size crabs was higher than that in the large body-size crabs. The animal diets, especially the crusion carp, was better than the corn and the formulated diets on the amino acid accumulation of the small body-size crabs. Nearly before the first molting, the essential amino acid and the total amino acid of the small body-size crabs fed with the sea-fish was significantly higher than those of the other four diets groups(P<0.05).And those of the large body-size crabs fed with the crusion carp was significantly higher than those of the other four diets groups(P<0.05). Both body-size crabs showed that the animal diets were better than the other kinds of diets in the final composition of the amino acid, especially the essential amino acid. 2. The energy densityof the whole individual showed that in the same diet group, the energy densityafter five-day’s feeding was significantly higher than that before feeding and nearly before molting(P<0.05). The energy densityin the stage firstly rised and then declined before the molting. After five-day’s feeding, the energy densityof the small body-size crabs in the crusion carp group was significantly lower than that in the corn group and the formulated diet group(P<0.05). And nearly before the molting, the energy densityof the large body-size crabs in the crusion carp group was also significantly lower than that in the corn group and the formulated diet group(P<0.05). This showed that the crusion carp was worse than the corn and the formulated diet in the energy supplement. 3. The content of the total lipid and the crude protein in the hepatopancreas were not significantly differences in different kinds of diets groups, or between different body-size crabs, or compared with three different time. This showed that the nutrition in the hepatopancreas were steady always in this stage. 4. The content of the total lipid and the crude protein in the muscle of the small body-size crabs declined from before feeding to the final before the molting. And the content of the crude protein of the large body-size crabs rised significantly in this stage(P<0.05). At the final time, before the molting, different body-size crabs were not significantly different with each other both in the total lipid and the crude protein. The content of crude protein in the crusion carp group was significantly higher than that in the corn group and the formulated diet, especially to the small body-size crabs(P<0.05).