We investigated the influence of intracellular diffusion on muscle fiber design in several swimming and non-swimming brachyuran crabs. Species with sustained swimming behavior had aerobic dark fibers subdivided into small metabolic functional units, creating short diffusion distances necessary to support the high rates of aerobic ATP turnover associated with endurance activity. This dark fiber ...

The ¢rst demonstration, to our knowledge, of an evolutionary shift in communication mode in animals is presented. Some species of Ovalipes display spectacular iridescence resulting from multilayer re£ectors in the cuticle. This re£ector is unique in animals because each layer is corrugated and slightly out of phase with adjacent layers. Solid layers are separated from £uid layers in the re£ecto...

Estuarine and nearshore marine areas are vital habitats for several fish and benthic invertebrates. The shore crab Carcinus maenas (Crustacea: Brachyura: Portunidae) inhabits a variety of coastal, estuarine and lagoon habitats. At low tide, habitat structural complexity may be most important for crabs in the intertidal, providing refuge from predation and desiccation. The quality of different v...