New evidence on the relationships between Hypnophila Bourguignat, 1859 and Gomphroa Westerlund, 1902 (Gastropoda: Eupulmonata: Azecidae)

Sinanodonta woodiana (Lea) and Corbicula fluminea (O. F. Müller) are among the most invasive aquatic molluscs found in Europe. Both species were recorded in the Adriatic part of Croatia for the first time in 2019 although in the Danubian Croatia they were more common. An abundant population of S. woodiana was found in an oxbow of the Cetina River; mussels with shell length of ca. 12–17 cm dominated. A population of C. fluminea was recorded in the freshwater section of the Zrmanja River above the Jankovića Buk waterfall which forms the border between the brackish and the freshwater sections of the river. Possible pathways of their introduction and reasons for their rare occurrence in contrast to the Danubian Croatia are discussed.