COREGONIDAE

Family COREGONIDAE

Genus Stenodus Richardson, 1836

12. Caspian Inconnu or sheefish Stenodus leucichthys (Guldenstadt, 1772)

It is an endemic to the Caspian Sea basin. In summer, sheefish inhabits the Middle and Southern Caspian Sea at depths to 50 m, while in autumn and winter they feed in the Northern Caspian Sea ( Vasilchenko, 2002). Before the regulation of the flow of the Volga River, this species migrated to spawn in its tributaries. Previously, sheefish had entered the Terek River, while some individuals went to spawn in the Ural River ( Letichevsky, 1963, 1972, 1975). It was a valuable commercial species, whose abundance has declined sharply. The main conservation measures for the preservation and recovery of its stocks are artificial propagation in fish hatcheries and a ban on fishing ( Matishov, 2010), as well as the inclusion of this species in the RDBs of the Russian Federation ( Pavlov, 2021), the Astrakhan region ( Pilipenko et al, 2014), the Republics of Kalmykia ( Ochirov, 2014) and Dagestan ( Magomedov, 2009), as well as Kazakhstan ( Meldebekov, 2010) (category IV as a poorly studied species) and Turkmenistan ( Annabayramov, 2011) (category III as a rare, declining species). The IUCN has classified the status of the sheefish as NT ( IUCN, 2024) due to the continued decline of this species’ population as a result of river flow regulation, pollution, habitat destruction and IUU fishing ( Matishov, 2010). As existing conservation measures, including artificial propagation, have not had the desired effect, this species requires additional protection.