節足動物の脚による吸水機構

抄録

The semi-terrestrial isopod, Ligia exotica, lives on the seashore among jetties and rocks. It shows poor resistance to desiccation and cannot live without seawater. When it is exposed to dry conditions, its body weight decreases to 90% of the initial weight within three hours. When subsequently presented with wet paper, legs VI- and VII-th of the animal are firmly apposed and stationed for a while. Since the body weight had increased after this behaviour, a pair of caudal legs seemed to play an important role to absorb water. Morphological observations of those caudal legs revealed that there is a series of thin cuticler protrusions, oriented in several parallel lines, which is developed on from 2nd to 5th podite of the VI-th preiopod and 6th podite of the VII-th pereiopod. When we immersed each leg from the tip, the water flows along those series of thin cuticler protrusions. The animal absorbs water along those surface structures of the caudal legs.