New locality records of invasive freshwater jellyfish Craspedacusta sowerbii (Lankester, 1880) in Türkiye

Invasive jellyfish Craspedacusta sowerbii (Lankester, 1880) is a hydrozoan (Phylum Cnidaria, Class Hydrozoa), most easily identified in its hydromedusa form as a small, bell-shaped jellyfish. Indigenous to the Yangtze River valley in China, this species has spread across temperate climates, including Türkiye, for over a century. In this study, three new locality records were discovered in Türkiye: Umurbey (Çanakkale), Geyik (Muğla), and Seyhan (Adana) dams. Some physicochemical parameters (pH, dissolved oxygen, temperature and electrical conductivity) of the sampling points were measured. Although there is no definite information on the origin of this species in the dams, it is thought that it is hypothesized that it may have been introduced by fish stocking, aquatic birds and human activities.