Preliminary Studies On The Autumn Seed Producing Techniques, Growth, Gonad Development And Feeding Eco-physiology Of Scallop Chlamys Farreri

Great losses have been caused in the scallop (Chlamys farreri) industry during the past 10 years in China because of the occurrence of its heavy mortality in summer, which has serious restricted the development of scallop aquaculture in China, and this situation is supposed to go even worse in the future if we cannot find the effective measures to control the situation. Up to now, no effective method dealing with this problem is determined though many concerned studies have been conducted considerably. According the biological feature of this species, there are spring and autumn spawning peaks during a year round. Traditionally, almost all hatcheries take the spring spawning season to produce the seeds of the scallop. The shell height of scallop from the spring seeds can reach to 5-6cm in the next June and then the gonads develop to mature phase easily and discharge ova or sperms subsequently under proper conditions. Thereafter, the physique of the spawned scallop becomes relatively weak and vulnerable of high-temperature in the following summer, which may causes the heavy mortality of scallop Chalmys farreri. Based on the observation and the learning of it biological feature, the development of gonad of autumn seed of scallop Chalmys farreri cannot reach to mature phase in the next June, so the resistance of high-temperature and other adverse factors is stronger than that of the spring-breeding ones, which makes it possible for the scallop to get through the summer season.In the study, autumn seeds of scallop Chlamys farreri were produced artificially from the late September of 2004 and over-wintered successfully in the indoor tank of hatchery, and then the seeds were cultured at sea in the next year. The growth and survival rate of the autumn seeds cultivated in the sea was observed and...