The Colonization of Land By Crustaceans

赖特9808144 onsicidean等足类或woodlice构成了唯一的主要群体的甲壳类动物殖民地的土地，和现存的动物群显示了一个不寻常的完整的代表性的进化辐射。至少有5个独立的谱系已经在陆地上定居，包括占据从潮间带到完全陆地的过渡栖息地的物种。这一点，再加上等足类动物发生学的最新进展，使得Oniscidea特别适合于进化生理学的研究。研究将侧重于四个主要系统的比较生理学，所有这些系统预计将在水生-陆生过渡期间进行重大的适应性修改：水蒸气吸收;氨和氮排泄的替代途径;血淋巴调节;以及胚胎的耐热性和耐渗透性。具体项目的例子包括研究膜运输在pleopodal鳃和可能的同源性之间的作用，在水蒸气吸收，潮间盐的排泄，和水生植物的调节。谱系内的比较生理学提供了一种了解水蒸气吸收和氨挥发等陆地适应的适应前基础的方法。谱系之间的比较将探讨不同的殖民路线-从高湿度和热稳定性的间隙栖息地的海洋沿岸的区的小气候极端都塑造和限制生理系统的进化。

Wright 9808144 The onsicidean isopods or woodlice constitute the only major group of crustaceans to have colonized land, and the extant fauna shows an unusually complete representation of evolutionary radiations. At least 5 independent lineages have colonized land, and include species occupying a number of transitional habitats from intertidal to fully terrestrial. This, combined with recent advances in isopod phylogeny, makes the Oniscidea particularly suited to studies of evolutionary physiology. Research will focus on comparative physiology of four main systems, all expected to undergo major adaptive modification during an aquatic-terrestrial transition: water vapour absorption; ammonotely and alternative avenues of nitrogenous excretion; haemolymph osmoregulation; and the thermal and osmotic tolerance of embryos. Examples of specific projects include studies of membrane transport in the pleopodal gills and possible homology between its role in water vapor absorption, intertidal salt excretion, and aquatic osmoregulation. Comparative physiology within lineages provides a means to understand the preadaptive basis of such terrestrial adaptations as water vapour absorption and ammonia volatilization. Comparisons between lineages will explore how different colonization routes - from the high humidity and thermal stability of interstitial habitats to the microclimatic extremes of the marine littoral zone have both shaped and constrained the evolution of physiological systems.