Exotic fishes in the southern Caspian Sea basin; with four new records

We listed 28 exotic fish species belonging to 22 genera, 15 families and 12 ordersfor Iranian part of the southern Caspian Sea basin, based on published records and specimens collected between 2000 and 2023. Their native distribution ranges, as well as occurrences in the Iranian waters are given, and the presence of four species is recorded for the first time from the region. Two species are new records for the whole country. The family containing the highest number of exotic species is Xenocyprididae(5 species) followed by Cyprinidae (4 species), Mugilidae and Poeciliidae (3 species each), and Salmonidae and Loricariidae(2 species each). Five species were determined to be invasive due to their wide distribution, established populations, and fast dispersal through the region (Gambusia holbrooki, Carassius gibelio, Hemiculter leucisculus, Pseudorasbora parva, and Rhinogobius cheni). Alien fishes have been introduced for a variety of reasons in the region, including ornament, sport, aquaculture, biological control, and by accident.