• All these results support the hypothesis that R. insulaepinorum should be con- sidered a synonym of the more widely distributed ‘R. cylindraceus’ (Huber, 1992; Murphy and Collier, 1996; Lara et al., 2010). However, the level of divergence of cytb sequences (dTN = 2.6%) between the two subclades of R. cylindraceus approaches that of subspecies level.