Genus Acipenser Linnaeus, 1758

3. Acipenser baerii Brandt, 1869 [I]-[EN], Siberian Sturgeon/Caspian Sea Basin (Hasanalipour et al., 2013). This species was imported for aquaculture purposes, but it can be found in some natural habitats e.g., Aras River, which probably escaped from fish farms.

4. Acipenser gueldenstaedtii Brandt & Ratzeburg, 1833 [N]-[CR], Russian sturgeon/Caspian Sea Basin (Esmaeili et al. 2018).

5. Acipenser nudiventris Lovetsky, 1828 [N]-[CR], Fringebarbel sturgeon/Caspian Sea Basin (Esmaeili et al., 2018).

6. Acipenser persicus Borodin, 1897 [N]-[CR], Persian sturgeon/Caspian Sea Basin (Eagderi et al., 2017a; Esmaeili et al., 2018).

7. Acipenser ruthenus Linnaeus, 1758 [N]- [VU], Sterlet/Caspian Sea Basin. Comment: Reported from the middle and South Caspian Sea by Naseka and Bogutskaya (2009) but not confirmed by specimens for Iran. This species is transported to the Shahid Rajaee Fish Aquaculture Center at Sari, Mazandaran, and some other fish farms in Guilan and Golestan provinces for aquaculture purposes.

8. Acipenser stellatus Pallas, 1771 [N]-[CR], Stellate sturgeon/Caspian Sea Basin (Esmaeili et al., 2018).