海湾扇贝浮游幼虫适宜饵料种类和密度

STUDY ON SUITABLE SPECIES AND DENSITY OF FOOD FOR FREE-SWIMMING LARVAE OF BAY SCALLOP,ARGOPECTON IRRADIANS

本文选用6种不同种类和不同密度的单胞藻作为海湾扇贝浮游幼虫的饵料,进行对比实验研究,从而提出了海湾扇贝浮游幼虫期最适宜的饵料种类与密度。

For the purpose to select suitable species and density of the food for the free-swimming larvae at the different developmental stages of Argopecten irradians,a series of comparative experiments were made.The results are as follows:1.Food should be given at the stage of veliger,At this stage,the larvae showed a preferable selection for the size of the feeding algae.2.Before the middle stage of umbo larvae,the larvae fed on the single food of Dicrateria zhanjiangensis and Isochrysis sp.,or mixed food of D.Zhanjiangensis and Chaetoceros calcitrans grew faster(9.6—10μm/d)with higher survival rate(90%)than the larvae f eding with other kinds of food.After the middle stage of umbo larvae,mixed food of D.zhanjiangensis,Isochrysis sp.were found to be better.3.Apart from the species of food,the density is also an important factor.Experiments showed the food density should be kept at 10000—25000 ind./ml at early free-swimming larvae,and gradually raised to 50000—100000 ind,/ml.