栉孔扇贝的食料分析

栉孔扇贝的食料以硅藻为主,作者在调查海区中共检查出硅藻79种,隶属于37属,扇贝胃含物中共检出59种,隶属于28属 栉孔扇贝易摄食的主要种类有舟形藻、圆筛藻、骨条藻、曲舟藻和金藻,选择指数较高;兼食一些绿藻、桡足类、无脊椎动物卵和幼虫及有机碎屑 栉孔扇贝对角毛藻、根管藻、楔形藻、甲藻类及纤毛虫类选择指数较小,其主要原因是这些生物有长的角毛、尖而硬的棘和刺,不易被鳃过滤和摄食。栉孔扇贝的食料随季节、海区的不同,食料的组成以及对食料的选择指数都有不同的变化。同一季节不同日期其食料组成也随着海区浮游生物的变动而变化 不同大小的扇贝在同一海区中其食料组成是类似的,无明显差异

ANALYSIS OF FOODSTUFFS FOR FARRER' S SCALLOP CHLAMYS (AZUMAPECTEN) FARRERI (JONES ET PRESTON)

Farrer' s Scallop relies on diatom as its main foodstuffs. In an investigation in the sea area in Qingdao, we have found 79 species of diatom under 37 genera; and we have also found in the stomach of the scallops 59 species of diatom belonging to 28 genera.The chief species of the algae liable to be taken in by the scallops are Navicula Concinodiscus, Skeletonema, Chrysophyta, etc., and these serve to show the scallop' s high selectivity index. The scallops may also eat some Chlorophyta, Copepods, eggs and larvae from invertebrates and organic detritus However the scallops exhibit a low selectivity index for Chaetoceros, Rhizosolenia, Licmophora, Pyrrophyta andciliates, chiefly because of their horny hairs, or pointed and hard spines and nodules, which arc difficult to be filtered through the scallop's gill,and have little chance to be selected.The food composition of the scallop and its selectivity index vary with the season and the location of the sea region Even in different days of the same season, the scallop's food composition will change with the daily change of the plankton's existence in the same sea area.For scallops of various sizes in the same region, their food composition is similar, indicating no distinct differences.