Ca++-ATPase activity in the hindgut epithelial cells ofOniscus asellus

Specialized junctional complexes and the ultrastructural morphology of the hindgut epithelial cells indicate that the terrestrial isopod hindgut epithelium functions in transport. The hindgut is divided into an anterior hindgut (typhlosole region), a posterior hindgut (papillate region) and a rectum. Using mitochondrial morphometry as an indicator of cell transport activity, Coruzzi et al. demonstrated that the posterior hindgut ofArniadillidium vulgareis active in osmoregulation to a greater degree thanO. asellus. A study was undertaken to determine if this difference is reflected in the CA++-ATPase activity of the hindgut epithelial cells ofO. asellus.