Insects in hypoxia

Insects exhibit a remarkable array of adaptations that allow them to handle more or less severe hypoxia associated with numerous aquatic and terrestri al habitats. We consider these habitats and then discuss physiological, beh avioral and morphological mechanisms that facilitate insect life under oxyg en deprivation. Actually or potentially hypoxic habitats include aquatic sy stems, flood-prone soils and burrows, intertidal zones, ice encasement and high altitudes. Some microhabitats, including dung, carrion, mammalian alim entary canals, grain and wood, also are subject to hypoxia. Adaptations to hypoxia include the ability to switch from aerobic to anaerobic metabolic p athways (with attendant generation of end products), the ability to drastic ally attenuate basal metabolic rates, altered behaviors and enlarged trache al system volumes. Research into the biology of hypoxia seems to be progres sing from early observations of the abilities of some insects to withstand exposure to hypoxia or anoxia through studies of organismal mechanisms oper ating in hypoxia to detailed investigations of cellular and intracellular s ignaling processes. Our hope is this essay will help crystallize the emerge nt picture of this area for those interested in contributing to future rese arch. (C) 2001 Elsevier Science Ltd. All rights reserved.