This study investigated the predation of different-sized juvenile jellyfish Rhopilema esculentum [（2.5±0.1）, （4.1±0.2）, （11.7±0.5）, and （21.1±-0.6）mm in umbrella diameter] on flounder Paralich thys olivaceus eggs [ （0.92±0.01）mm in diameter] and newly-hatched larvae [（3.01±0.08）mm in total length] at different prey densities （10, 30, 50, 80ind/L）. In addition, the predation rates of juvenile jellyfish [（21.1±0.6）mm in umbrella diameter] on newly-hatched larvae at different predation duration （0.5, 1, 2, 3, 4, 5h） were examined. In all size-groups, the predation rates on eggs were significantly lower than that on newly-hatched larvae at all prey densities. Neither egg density nor jellyfish size had significant effect on the predation rates. Predation rates on larvae increased significantly with the increase of jellyfish size and larval density. Predation rates on larvae by the juvenile jellyfish （21.1mm in diameter） reached a maximum of 17.3ind/（predator.h） at lh, and then dropped gradually as the predation duration was prolonged. It is assumed that predation on eggs and larvae by juvenile jellyfish could influence the embryonic and larval survival of the flounder if the predators and prey were spatially and temporally matched in nature, which could subsequently affect the recruitment or the population dynamics of the flounder populations.%利用实验生态学方法研究不同个体大小的海蜇浮游幼体[平均伞径（2．5±0．1），（4．1±0．2），（11．7±0．5），（21．1±0．6）mm]对不同密度（10，30，50，80ind／L）的褐牙鲆卵[卵径（0．92±0．01）mm]和初孵仔鱼f全长（3．01±0．08）mm]的捕食率，解析海蜇浮游幼体对初孵仔鱼的捕食率随捕食时间（0．5，1，2，3，4，5h）的变化特征。结果表明，各个体组海蜇浮游幼体对卵的捕食率均显著低于对仔鱼的捕食率；它们对卵的捕食率与卵密度和海蜇个体大小的关系不显著，但对仔鱼的捕食率随海蜇个体大小及仔鱼密度的增大而显著升高；伞径21．1mm的个体对仔鱼的捕食率在开始捕食后1h时达到最大值[17．3ind／（predator．h）]，此后随捕食时间的延长而逐渐下降。在自然水域中，如果二者发生时空上的匹配关系，海蜇浮游幼体对仔鱼的捕食可能影响褐牙鲆的早期存活及其资源补充量的变动。
展开▼
