Evolutionary adaptation of oniscidean isopods to terrestrial life: Structure, physiology and behavior

Terrestrial isopods (Oniscidea) are the most successful crustacean colonizers of land habitats. From an evolutionary point of view, they are excellent examples of model organisms that have adaptated to terrestrial life. The aquatic-terrestrial branching of the phylogenetic lines of the Oniscidea occurred in the marine littoral zone. The most oniscid species-rich areas are found in the circum-Mediterranean region. Studies on the morphology, physiology, ecology and biogeography of Oniscidea highlight the diversity of the group. They successfully colonized a wide range of terrestrial habitats by solving such ecological and physiological challenges as reproduction, respiration, excretion and protection against desiccation. During terrestrial adaptation, they evolved diverse morphological, ecological and behavioral traits. This review summarizes our present knowledge of some aspects of the morphology, physiology and behavior as it related to oniscidean adaptation to the terrestrial realm.