Adaptive Phenotypic Plasticity in an Aquatic Community

春季在北海道周边的森林中形成的池塘群落的建立者是无尾蛙蝌蚪和小鲵幼体。蝾螈幼体在一定条件下发育成宽头型。蝾螈幼虫有一个广泛的头部变形是一个强大的捕食者，有能力吞下同种幼虫和蝌蚪与一个大的张口大小。宽头形态被认为是一种适应性表型可塑性。蝌蚪也表现出表型可塑性。当它们暴露在幼蝾螈的捕食风险中时，蝌蚪会发育出一个凸出的身体。这种膨胀阻止了有着巨大嘴巴的蝾螈的吞食。蝾螈幼虫面包头和蝌蚪凸出体的可塑性被认为是捕食者-被捕食者相互作用的对抗性协同进化，蝌蚪对群落中的其他捕食者表现出另一种类型的可诱导防御形态。蜻蜓幼虫是池塘群落中最常见的捕食者之一。当蝌蚪暴露于蜻蜓幼虫的捕食风险时，它们会发展出更高的尾部形态。蝌蚪的R. pirica具有两种类型的诱导防御形态。一种是诱导形态学对蝾螈幼体捕食风险的专化型诱导形态学，另一种是诱导形态学对池塘群落中各种捕食者的通才型诱导形态学。

Anuran tadoles of Rana pirica, and salamander larvae of Hynobius retardatus are the founders of the ponds community that are formed in forests peripheral in Hokkaido in spring. The salamander larvae become a broad headed morph in the larval developmental period in certain condition. Larval salamanders having a broad headed-morph are a strong predator that has an ability to swallow conspecific larvae and tadpoles with a large gape size. The broad-headed morph is considered as an adaptive phenotypic plasticity. The tadpoles also exhibit a phenotypic plasticity. The tadpoles develop a bulgy body when they are exposed to the predation risk of the larval salamanders. The bulginess prohibits being swallowed by the salamanders having a large gape. The plasticity of larval salamander, bread-head, and of tadpole, bulgy body, are considered as antagonistic coevolution of predator-prey interaction.The tadpoles exhibit the other type of inducible defense morphology to the other predator species in the community. Dragon fly larvae are one of the commonest predator species in the pond community. The tadpoles develop higher tail morphology when they are exposed to the predation risk of the dragon fly larvae. Tadpoles of R. pirica have two types of inducible defense morphologies. One is the specialist type inducible morphology to the predation risk of the larval salamander, and the other on is the generalist type one to the various other predator species in the pond community.