A cave leech (Hirudinea, Erpobdellidae) from Croatia with unique morphological features

Abstract

Croatobranchus mestrovi is a troglobitic leech from deep shaft‐like caves in the Velebit Mountain, Dinaric karst, Croatia, living in cold (4–6 °C) water. Its oral sucker extends to form four pairs of triangular tentacles, each with about five finger‐like papillae, but widening into a marginally crenulated disc when attached to a substrate. Pairs of stiff, finger‐like lateral projections, probably gills, occur along the body behind the clitellum. Somites are simple five‐annulate. Despite the unique head morphology and the presence of lateral outgrowths, the anatomy and 18S rRNA gene sequence of this species indicate that it is a member of the Erpobdellidae, closely related to Dina .