Iwami Tadashi, Kishida Osamu, Nishimura Kinya
Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido, Japan.
PLoS One. 2007 Oct 31;2(10):e1084. doi: 10.1371/journal.pone.0001084.
Organisms often exhibit phenotypic plasticity in multiple traits in response to impending environmental change. Multiple traits phenotypic plasticity is complex syndrome brought on by causal relations in ecological and physiological context. Larvae of the salamander Hynobius retardatus exhibit inducible phenotypic plasticity of two traits, when at risk of predation by dragonfly larvae. One induced phenotype is an adaptive defense behaviour, i.e., stasis at the bottom of water column, directly triggered by the predation risk. Another one is a compensatory phenotype, i.e., enlarged external gills, for an unavoidable cost (hypoxia) associated with the induced defense. We identified two ways by which this compensatory phenotype could be induced. The compensatory phenotype is induced in response to not only the associated hypoxic conditions resulting from the induced defense but also the most primary but indirect cause, presence of the predator.
生物通常会在多个性状上表现出表型可塑性，以应对即将到来的环境变化。多性状表型可塑性是生态和生理背景下因果关系导致的复杂综合征。当日本林蛙的幼体面临被蜻蜓幼虫捕食的风险时，它们会在两种性状上表现出可诱导的表型可塑性。一种诱导表型是适应性防御行为，即停留在水柱底部，这是由捕食风险直接触发的。另一种是补偿性表型，即外部鳃增大，以应对与诱导防御相关的不可避免的代价（缺氧）。我们确定了两种可以诱导这种补偿性表型的方式。补偿性表型不仅会因诱导防御导致的相关缺氧条件而被诱导，还会因最主要但间接的原因——捕食者的存在而被诱导。
