Occurrence of Two Non-indigenous Alien Sea Slugs, Bursatella leachii (Blainville, 1817) and Melibe viridis (Kelaart, 1858) (Gastropoda: Heterobranchia), from the Canakkale Strait, Turkish Straits System

This study reports the heterobranch mollusks Bursatella leachii (Blainville, 1817) and Melibe viridis (Kelaart, 1858) for the first time from the Dardanelles ((anakkale Strait), Turkey. Individuals of these two species were observed in January 2020 on a sandy and seagrass bed of Cymodocea nodosa (Ucria) Ascherson and in groups among the algae Caulerpa racemosa (Forsskal) J. Agardh. Although the Dardanelles is one of the biodiversity hotspots in Turkish Seas and the abundance of marine invertebrates in particular regions is significantly high, the inventory of the sea slugs in the region is limited. This study improves the existing knowledge on the molluscan fauna of the Turkish Straits System, the species abundance in the region and their ecological characteristics. The current finding also represents the northernmost records in an invaded area at the Canakkale Strait of Aegean Sea.