底物中钙赋存形态对太平洋牡蛎(Crassostrea gigas)幼虫附着的诱导效应

EFFECT OF CALCIUM FORM IN SUBSTRATE AND LARVAE ABUNDANCE IN SEAWATER ON SPAT SETTLEMENT OF PACIFIC OYSTER CRASSOSTREA GIGAS

为探讨底物中钙赋存形态对牡蛎幼虫附着的诱导效应,本研究设计3因子随机区组实验,检验实验底物钙含量、钙赋存形态及海水中牡蛎幼虫丰度对实验底物上太平洋牡蛎(Crassostrea gigas)稚贝附着效果(密度和壳高)的影响。结果表明,在3个因子中,实验底物钙含量对附着稚贝密度和壳高的影响不显著(P>0.05),而其它2个因子(钙赋存形态和海水中牡蛎幼虫丰度)均显著影响着实验底物上附着牡蛎稚贝的密度和壳高(P<0.05)。在相同的牡蛎浮游幼虫丰度下,3种钙形态底物对牡蛎幼虫附着的诱导能力大小顺序为:有机钙>碳酸钙=硫酸钙(P<0.05);壳高的结果却恰恰相反。在同样的钙形态底物中,高牡蛎幼虫丰度下牡蛎稚贝附着量均显著高于低幼虫丰度的处理组(P<0.05)。

To understand whether calcium in different forms m substrate of artificial reefs could affect oyster spat settlement, we designed an experiment with calcium in different forms and concentrations, and oyster larvae abundances in seawater in three-factor randomized manner. The density and shell height of spats attached onto substrate were measured. Results show that calcium concentration （10%, 60%） showed no significant effect on the density and shell height （P〉0.05）. However, both calcium forms and planktic larvae abundance affected significantly the density and shell height of settled oyster spat in substrate （P〈0.05）. The order of impact of three calcium forms on the settlement was organic calcium 〉 carbonate calcium = sulfate calcium in an identical oyster larvae abundance in seawater, while for the shell height, the order was opposite. The density of oyster spat settled was greater in high abundance of oyster larvae than in low abundance （P〈0.05） regardless of calcium forms. Therefore, organic calcium could induce the settlement of oyster larvae significantly