Taylor Jennifer R A, Kier William M
Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
Nature. 2006 Apr 20;440(7087):1005. doi: 10.1038/4401005a.
Like their aquatic counterparts, terrestrial crabs repeatedly shed their rigid exoskeleton during moulting. But in the case of land crabs, little water is available to provide a temporary hydrostatic skeleton before the new skeleton hardens, and air does not provide the buoyancy necessary to support the animal. Here we show that whenever its exoskeleton is shed, the blackback land crab Gecarcinus lateralis relies on an unconventional type of hydrostatic skeleton that uses both gas and liquid (a 'pneumo-hydrostat'). To our knowledge, this is the first experimental evidence for a locomotor skeleton that depends on a gas. It establishes a new category of hydrostatic skeletal support and possibly a critical adaptation to life on land for the Crustacea.
与它们的水生同类一样，陆生螃蟹在蜕皮过程中会反复蜕去坚硬的外骨骼。但对于陆地螃蟹来说，在新骨骼硬化之前几乎没有水来提供一个临时的静水骨骼，而且空气也无法提供支撑动物所需的浮力。我们在此表明，黑背陆蟹（Gecarcinus lateralis）在每次蜕去外骨骼时，都依赖一种非常规的静水骨骼，这种骨骼同时使用气体和液体（“气-液压静力骨骼”）。据我们所知，这是首个关于依赖气体的运动骨骼的实验证据。它确立了一种新的静水骨骼支撑类别，可能也是甲壳纲动物对陆地生活的一种关键适应。
