香港巨牡蛎对3种浮游植物摄食率和滤清率的研究

本文在室内条件下研究了大、中、小3种规格的香港巨牡蛎（Crassostrea hongkongensis）对牟氏角毛藻（Chaetoceros muelleri）、亚心形扁藻（Platymonas subcordiformis）、球等鞭藻（Isochrysis galbana）3种浮游植物在同等密度、同等生物量条件下的摄食率和滤清率，探讨了香港巨牡蛎对3种浮游植物的摄食差异及其影响因素。结果表明，在28℃水温条件下，香港巨牡蛎的单位个体滤清率和单位体质量滤清率分别为1.40~8.94 L/（ind·h）和0.86~3.17 L/（g·h），等密度和等生物量浮游植物条件下香港巨牡蛎均表现出单位个体滤清率由高到低依次为:大规格、中规格、小规格；不同规格香港巨牡蛎的单位体质量滤清率相近。相同藻类密度条件下，香港巨牡蛎的单位体质量滤清率由高到低依次为:亚心形扁藻、球等鞭金藻、牟氏角毛藻；相同生物量条件下，香港巨牡蛎对3种浮游植物单位体质量滤清率由高到低依次为:球等鞭金藻、亚心形扁藻、牟氏角毛藻。香港巨牡蛎对不同浮游植物种类和密度的滤清率、摄食率差异主要是受饵料的大小、营养质量和密度等因素影响。

Research of clearance rate and filtration rate of Crassostrea hongkongensis feeding on three different phytoplankton

The clearance rate and filtration rate of Crassostrea hongkongensis feeding on Chaetoceros muelleri, Isochrysis galbana and Platymonas subcordiformis were examined using the lab experiments under the conditions of same density and biomass of phytoplankton by three different size of C. hongkongensis to discuss the feeding preference and impact infactors on phytoplankton of C. hongkongensis.The results showed that at temperature 28℃, the clearance rate per gram and per individual were 0.86-3.17 L/(g·h) and 1.40-8.94 L/(ind·h) respectively. The clearance rate per individual of C. hongkongensis presented as big-size> medium-size> small-size in the both case of same density and biomass of three phytoplankton, while the clearance rate per garm of C. hongkongensis was similar in spite of the size of C. hongkongensis. The changing pattern of clearance rate per individual presented as Platymonas subcordiformis > Isochrysis galbana > Chaetoceros muelleri under the condition of same density of three phytoplankton, while presented as Isochrysis galbana > Platymonas subcordiformis > Chaetoceros muelleri under the condition of same biomass of three phytoplankton. The different clearance rate of C. hongkongensison to different phytoplanton was mainly due to factors such as the food particle size, density and nutritive value.