Epizoic rotifers (Rotifera : Monogononta, Bdelloidea) from the gill chambers of Potamon fluviatile (Herbst, 1785)

We describe some rare epizoic rotifers found on Potamon fluviatile (Herbst, 1785) from Italy. Three species are discussed: Lecane branchicola (Piovanelli, 1903) (Monogononta, Lecanidae; new synonym: L. piovanellii Bartos, 1957), Anomopus telphusae Piovanelli, 1903 and Embata parasitica (Giglioli, 1863) (Bdelloidea: Philodinidae). Lecane branchicola, previously considered a nomen nudum after Bartos (1957), is redescribed, and its identity is stabilized by the designation of a neotype. Both L. branchicola and A. telphusae are particularly rare, and have been found on a few occasions only. Lecane branchicola appears to be restricted to a specific body part of their host, namely the branchial chamber. On the contrary, E. parasitica has been recorded as epizoic from several hosts and regions. SEM photographs of the trophi of the three species are presented.