PRELIMINARY STUDY ON REARING SPATS OF BULLACTA EXARATA (PHILIPPI)
Wang Yinong,Gu Xiaoying,You Zhongjie, Huang Laiya and Yang Maochao(Fisheries Dep. ,Ningbo University,Ningbo 315211)
Bullacta exarata (Philippi) is monoecious, reproduction is by crossfertilization. The reproduce period is from the end of March to the last ten-days of November along the coast of Zhejiang Province. The fertilized egg is protected by an egg-capsule membrane. After cleavage, it is developed to gastrula,then trochophora larva,which incubates at the viliger larva stage. During artificial spats-rearing,potassium permanganate [0. 28 - 0. 9(×10-6)]can increase hatching rates. During viliger and pediveliger rearing,potassium permanganate [0. 5 - 1 (×10-6)]or formalin [5 -10( × 10-6)] can reduce the amount of destructive microbes and animalcules. In the pediveliger stage,it must put in adherent sea-mud.This paper presents artifical spats-rearing technology in various stages,suggests how to increase hatching rates and discusses the drugs during the rearing period.