Gammoudi, MehrezBulnes, Veronica N.Kurt, Guley2025-03-232025-03-2320211108-393Xhttps://doi.org/10.12681/mms.24666https://hdl.handle.net/11486/5120Between October 2013 and July 2014, 40 polyclad specimens were collected during systematic sampling of mussel beds along the coast of the Sinop Peninsula (Western Black Sea). Six species were identified, including a new Cryptocelis species. Cryptocelis sinopae sp. nov. is characterized by possessing a prostatic vesicle lined with a ridged fold in its anterior end and the presence of two secretory glandular folds in the distal dorsal wall of the male atrium. Additionally, new records of Echinoplana celerrima Haswell, 1907 and Leptoplana mediterranea (Bock, 1913) are reported for Turkey and the Black Sea, as well as Leptoplana tremellaris (Muller OF, 1774) and Prosthiostomum siphunculus Delle Chiaje, 1822 for the coast of the Black Sea of Turkey. A short description of the reproductive behaviors of Pleioplana okusi Bulnes, Kalkan and Karahan, 2009 and Cryptocelis sinopae sp. nov. are provided.eninfo:eu-repo/semantics/openAccessMarine flatwormsmussel bedsecretory glandular foldtaxonomydiversityreproductive behaviorArticle22114115610.12681/mms.246662-s2.0-85109133726Q1WOS:000636429700011Q1