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Anzali Wetland is one of the most important Iranian wetlands on the shores of the Caspian Sea, and in addition to having exclusive fish, it is a valuable area for the migration and spawning of anadromous migratory fish. The present study was carried out in 4 main wetland basins, including Abkanar, Siah-Keshim, Sorkhankal and Sheijan, as well as 4 Rogas and the downstream of 4 important rivers of the wetland (Bahambar, Masul-Rodkhan, Siah-Darvishan and Pasikhan). Fish sampling was done from January 2023 to June 2024 with the aim of identifying the spawning areas of wetland fish and those migrating to the wetland, and the length of adults and juveniles, and the gender and stages of sexual maturity of adult fish were determined in the sampling area or inside the laboratory. The results showed that the fishes belonged to 40 species from 16 families, and 30, 30 and 26 species were identified in the Wetland basins, Rogas and all the rivers, respectively. Ecologically, 26 species are freshwater fish, 7 species migrate to rivers, 5 estuarine species and 2 species are multi-habitat. Also, 10 non-native species and 30 native or endemic species. In all the study areas of Anzali wetland including the 4 areas of the wetland, the Rogas and downstream of the important rivers entering the wetland, Rhodeus caspius with 29.9%, Gambusia holbrooki with 24.8%, Alburnus chalcoides 11.3% and Carassius gibelio with 9.9% were dominant. Spawning of Cyprinus carpio, Alburnus hohenackeri, Blicca bjoerkna, Esox lucius, Cobitis saniae and Rhodeus caspius in 25 to 32 stations, Ponticola gorlap, Proterorhinus nasalis and Sabanejewia caspia between 13 and 17 stations, Tinca tinca, Scardinius erythrophthalmus, Leucaspius delineatus and Pungitius platygaster in 6 to 11 stations out of 35 stations It was done and the lowest spawning areas were related to Silurus glanis, Luciobarbus capito and Perca fluviatilis. The non-native fishes G. holbrooki, Hemiculter leucisculus, Carassius gibelio and Pseudorasbora parva have large spawning areas in the lagoon and formed small to large populations. Also, the spawning of migratory fish, including Sander lucioperca and Rutilus lacustris, took place in 2 stations, and the spawning of Rutilus frisii, Vimba persa and Alburnus chalcoides took place in the lower reaches of the rivers, and with low probability in the Anzali lagoon, but the spawning of 2 other species of migratory fishes (Caspiamyzon wagneri and Abramis brama) was not determined. It seems that the most important way to preserve the wetland fish stocks is to preserve the wetland ecosystem, especially by increasing the useful depth of the wetland by dredging the ponds and not only the outlets that prevent the progress of aquatic, floating and submerged plants, also, the control of the entry of pollutants (especially the operation of treatment plants) into the wetland and besides, the protection of spawning areas in the spring season and the annual release of fish fingerlings of species with a critical condition such as S. lucioperca and P. fluviatilis, S. glanis, Leuciscus aspius, T. tinca, R. lacustris, A. brama and L. capito) be more important than other cases.
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