Williams Elizabeth A, Craigie Alina, Yeates Alice, Degnan Sandie M
School of Integrative Biology, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
Biol Bull. 2008 Aug;215(1):98-107. doi: 10.2307/25470687.
The initiation of metamorphosis in marine invertebrates is strongly linked to the environment. Planktonic larvae typically are induced to settle and metamorphose by external cues such as coralline algae (Corallinaceae, Rhodophyta). Although coralline algae are globally abundant, invertebrate larvae of many taxa settle in response to a very limited suite of species. This specificity impacts population structure, as only locations with the appropriate coralline species can attract new recruits. Abalone (Gastropoda, Haliotidae) are among those taxa in which closely related species are known to respond to different coralline algae. Here we identify highly inductive natural cues of the tropical abalone Haliotis asinina. In contrast to reports for other abalone, the greatest proportion of H. asinina larvae are induced to settle and metamorphose (92.8% to 100% metamorphosis by 48 h postinduction) by articulated corallines of the genus Amphiroa. Comparison with field distribution data for different corallines suggests larvae are likely to be settling on the seaward side of the reef crest. We then compare the response of six different H. asinina larval families to five different coralline species to demonstrate that induction by the best inductive cue (Amphiroa spp.) effectively extinguishes substantial intraspecific variation in the timing of settlement.
海洋无脊椎动物变态的起始与环境密切相关。浮游幼虫通常会被外部线索诱导沉降并变态，例如珊瑚藻（珊瑚藻科，红藻门）。尽管珊瑚藻在全球范围内都很丰富，但许多分类群的无脊椎动物幼虫仅对非常有限的一组物种做出沉降反应。这种特异性会影响种群结构，因为只有拥有合适珊瑚藻物种的地点才能吸引新的定居者。鲍鱼（腹足纲，鲍科）属于已知密切相关物种对不同珊瑚藻有不同反应的分类群。在这里，我们确定了热带鲍鱼黑唇鲍的高诱导性自然线索。与其他鲍鱼的报道不同，黑唇鲍幼虫的最大比例是由双叉节藻属的有节珊瑚藻诱导沉降并变态的（诱导后48小时内变态率为92.8%至100%）。与不同珊瑚藻的实地分布数据比较表明，幼虫可能在礁顶的向海一侧沉降。然后，我们比较了六个不同的黑唇鲍幼虫家族对五种不同珊瑚藻物种的反应，以证明最佳诱导线索（双叉节藻属）的诱导有效地消除了沉降时间上的大量种内变异。
