PHYSIOLOGY OF TERRESTRIAL ISOPODS

1. This article reviews the physiology of oniscidean isopods, a group of terrestrial crustaceans known commonly as woodlice or sowbugs. 2. T he oniscideans are represented by several hundred species in 34 famili es and occupy habitats ranging from sea beach to woodland, grassland a nd desert. 3. The widespread interest in woodlice stems, in part, from their evolutionary transition from marine to terrestrial habit direct ly over sea beaches. Representative stages of this evolutionary transi tion are extant within the oniscidean group. 4. Water and water relati ons have featured prominently in the accession to land by woodlice; co nsequently, these topics have been the focus of much historical and re cent research work. The present review builds on a strong foundation o f behavioural research on water relations and explores the evolutionar y success of these unique crustaceans from a physiological point of vi ew, emphasizing recently published work. 5. Topics include gas exchang e and effects on VO2, marsupial adaptations, water-vapour absorption, ammonia excretion, moulting and its neuroendocrine control, nutrition and osmotic regulation.