A review of the alien fishes of Turkish inland waters

Abstract

Aquaculture, recreational fishing, restocking, biological control, and the ornamental fish trade have increased the number of nonnative fish in Turkish inland waters. This work reviews the history, current state, and tendencies of fish introductions into Turkish freshwaters. To date, it is known that a total of 34 exotic species (except two marine and three misidentified species) have been introduced deliberately or accidentally into Turkish inland waters, of which, only 19 species have been established in wild ecosystems. A total of five acclimatized species, viz. Coregonus lavaretus, C. macrophthalmus, Salmo salar, Salvelinus alpinus, and S. fontinalis and four species, viz. Hypophthalmichthys molitrix, Ictalurus punctatus, Oreochromis mossambicus, and Sarotherodon galilaeus that still live in closed systems were excluded from the ichthyofauna list of Turkey. The current presence of six species, viz. Acipenser baerii, Hemichromis letourneuxi, Heteropneustes fossilis, hybrid Morone (M. chrysops × M. saxatilis), Pangasius sanitwongsei, and Pygocentrus nattereri needs confirmation as to whether they have been surviving or not in the wild. Some established species, including Carassius gibelio, Gambusia holbrooki, Lepomis gibbosus, and Pseudorasbora parva are considered invasive, and Gymnocephalus cernua is also spreading into the Trachea region.