多棘海盘车对太平洋牡蛎、紫贻贝、菲律宾蛤仔摄食选择性的研究

Study on the Prey Selection of Sea Stars(Asterias amurensis)Preying on Juvenile Oysters(Crassostrea gigas),Mussels(Mytilus edulis) and Clams(Ruditapes philippinarum)

以多棘海盘车(Asterias amurensis)为试验对象,研究了多棘海盘车对3种双壳贝类的摄食选择性、摄食过程中用于搜寻和处理饵料生物的时间分配以及摄食机制等。试验以选择指数、捕食速率、日平均摄食率对多棘海盘车的摄食行为及搜寻和处理时间比进行了描述和统计。结果表明:各处理组多棘海盘车对菲律宾蛤仔的选择指数均为最高,占3种饵料生物的70%以上,显著高于太平洋牡蛎和紫贻贝(P<0.05),而各处理组对太平洋牡蛎的选择性均最低。多棘海盘车对菲律宾蛤仔的捕食速率和日平均摄食率显著高于太平洋牡蛎和紫贻贝。研究发现,在各处理组中多棘海盘车用于搜寻饵料生物的时间无显著差异,但随饵料密度的增加,用于处理饵料的时间逐渐减少。

Experiments were carried out to investigate the effect of prey density on predation, prey selec- tion and component behaviors which were examined by presenting individual sea star （Asterias amurensis） with combination of three bivalves. We quantified prey selection indexes, predation rates, daily average feeding rate, and proportion of time spent searching and handling prey and prey characteristics to indentify mechanisms underlying predation patterns and selection of prey. Daily average feeding rates of sea stars showed that sea stars predated oysters was not changed with the prey relative abundance. Examination of behaviors indicated that time spent searching prey by A. amurensis was not changed significantly among experimental groups, but time spent handling prey was decreased along with the increase of prey density. These results provide the reference for bivalves＇ population enhancement operations and bottom aquacul- ture.