Ultrastructure of the Statocyst in an Undescribed Species of Luridae (Platyhelminthes, Rhabdocoela, Luridae)

Abstract

The statocyst of an undescribed species of Luridae is described by electron microscopy. it is located between the brain and the intestine, suspended on a cytoplasmic band, and contains a nucleus and three statoliths. The statoliths are surrounded by many mitochondria. Fibres from the brain enter the statocyst wall through dark lamellae with a lamellate substructure, and form part of the wall that contains many basal bodies with short axonemes which, however, do not protrude into the statocyst cavity as free cilia. It is not clear whether intestinal cells contribute to the formation of the statocyst wall. Three small statoliths, also surrounded by many mitochondria, lie in cytoplasm latero-posteriorly to the statocyst.