早熟河蟹的养殖生态学及其渔业价值评价

CULTURAL ECOLOGY OF MATURE YEARLING CHINESE MITTEN-HANDED CRAB, ERIOCHEIR SINENSIS (CRUSTACEA,DECAPODA), AND ITS FISHERY EVALUATION

把池塘育成的早熟河蟹（即一秋龄性腺成熟中华绒螯蟹）放养于湖汊，其群体越冬成活率为11％。在第二年养殖期间，早熟河蟹不脱壳，体重维持在原来的水平，对鱼肉的日摄食率最高为1．2％，个体不断死亡，至7月中旬，群体全部死完。从当年11月下旬到第二年7月上旬，早熟河蟹成活率曲线公式为：Y=1．09exp（－0018t）［Y：成活率（％），t：时间（d）］。本文还通过对围栏湖汊和扁担塘早熟河蟹逐月跟踪采样、对同龄的末成熟与成熟河蟹的行为及离水成活时间进行对比观察。作者认为，草型湖泊中早熟河蟹没有养殖价值，但若在第二年四月份以前将早熟河蟹全部起捕，当商品蟹出售，仍有一定的渔业效益．

The overwintering survival rate of the mature yearling Chinese mitten-handed crab, Eriocheir sinensis, was 11%. The survinal curve can be expressed as Y=1.09exp (-0.018x)(Y:survival rate, x:days) from Dec. to Jul. During cultivation period in a small basin (3.3 hm2) of Bac’ An lake, the drily feeding rate of mature crabs was not higher than 1.2% when fed on fish meat. The mature crabs did not cast off their crusts, and the last one died in the middle of July. On the basis of samples of mature crabs in Biandan-tang lake and the small bay, and obersavations of the crabs’behavior and the survival rate of the mature crabs, it is proposed that the mature yearling crabs may not be suitable for aquaculture in macrophytic lakes. But the precocious crabs can be harvested before April each year.