Bdelloid

The bdelloids (Bdelloidea) are a class of rotifers, found in freshwater and moist soil. They typically have a well developed corona, divided into two parts, ona retractable head. They may move by swimming or crawling. Bdelloids have been of interest to those interest in the evolutionary role of sexual reproduction, because it has disappeared entirely from the group: males are unknown, and females reproduce exclusively by parthenogenesis. Each individual has paired gonads.