Habitat partitioning and thermal tolerance in a tropical limpet, Cellana grata

Abstract

Populations of C. grata were studied on exposed shores around Cape d'Aguilar, Hong Kong. Limpets moved up to 1 m in the vertical plane over a tidal cycle. When not foraging limpets took refuge in habitats that reduced the effects of high temperature and desiccation stress. The quality of these refuges varied both spatially and temporally. Experimental manipulations with specimens restrained 0.5 m above their normal resting height or on horizontal rock surfaces and prevented from returning to refuges caused desiccation, osmotic stress and, in many cases, death as a consequence of prolonged emersion. C. grata exhibits "mushrooming' behaviour, lifting its shell from the rock surface, although the exact benefits of this behaviour are unclear. Summer physical extremes may strongly select for limpet activity rhythms. -from Authors