Elbourne Peter D, Veater Robert A, Clare Anthony S
School of Marine Science and Technology, Newcastle University, Newcastle upon Tyne, UK.
Biofouling. 2008;24(2):87-96. doi: 10.1080/08927010701802565.
Gregariousness in marine invertebrate larvae is an important regulator of benthic community structure. Previous laboratory settlement assays employing Balanus amphitrite Darwin cyprids found gregarious effects with as few as 3 larvae well(-1), together with modulation of such effects by chemical cues. Here, the relationship between settlement rate and larval density was rigorously tested through a fully randomised design. Seawater conditioned with adult B.amphitrite was tested alongside unconditioned seawater to determine the effect of a conspecific cue on gregarious interactions. Gregarious effects were detected in both conditioned and unconditioned seawater at < or =4 larvae well(-1). In untreated seawater, settlement rate increased linearly with larval density, levelling off at densities of > or =10 larvae well(-1). In conditioned seawater, settlement induction was observed at < or =4 larvae well(-1), switching to inhibition at 6, 8 and 10 larvae well(-1), before asymptoting at the highest densities tested. These results advocate the use of individual larvae in laboratory assays that investigate factors stimulating barnacle settlement.
海洋无脊椎动物幼虫的群居性是底栖生物群落结构的重要调节因素。先前使用白脊藤壶达尔文无节幼体进行的实验室附着试验发现，每孔低至3只幼虫时就存在群居效应，同时化学信号会调节这种效应。在此，通过完全随机设计对附着率与幼虫密度之间的关系进行了严格测试。用成年白脊藤壶处理过的海水与未处理的海水一起进行测试，以确定同种信号对群居相互作用的影响。在每孔≤4只幼虫的条件下，在处理过的海水和未处理的海水中均检测到群居效应。在未处理的海水中，附着率随幼虫密度呈线性增加，在密度≥10只幼虫/孔时趋于平稳。在处理过的海水中，在每孔≤4只幼虫时观察到附着诱导，在6、8和10只幼虫/孔时转变为抑制，在测试的最高密度下趋于稳定。这些结果提倡在研究刺激藤壶附着因素的实验室试验中使用单个幼虫。
