Acipenser ruthenus Linnaeus, 1758 – Native (Fig. 22) Acipenser ruthenus Linnaeus [C.] 1758: 237; Type locality:? Danube River. Holotype: NRM 96. based on several sources this specimen may be the holotype, see Kottelat (1997). Acipenser koster Gmelin [J. F.] 1789: 1486; Type locality: Caspian Sea. Acipenser pygmaeus Pallas [P. S.] 1814: 102; Type locality: Major seas and rivers of Europe. No types known. Acipenser kostera Fitzinger [L. J. F. J.] 1832: 340; Type locality: Danube River, Vienna, Austria. Neotype: BMNH 1898.4.11.26. Acipenser marsiglii Brandt [J. F.] in Brandt & Ratzeburg 1833: 352; Type locality: Danube River or Ob River. Holotype:? ZIN 11825. Acipenser kamensis Lovetsky [A.] 1834: 262; Type locality: Kama River, Russia. No types known. Acipenser aleutensis Fitzinger [L. J. F. J.] in Fitzinger & Heckel 1836: 285; Type locality: Canaga Island, Aleutian Islands, Alaska, U.S.A. [in error]. No types known. Acipenser gmelini Fitzinger [L. J. F. J.] in Fitzinger & Heckel 1836: 276; Type locality: Azov Sea or Caspian Sea. Holotype (unique): NMW (not found). Acipenser ruthenus var. grisescens Brandt [J. F.] 1853: 320; Type locality: Nishni-Novgorod, Russia. No types known. Acipenser ruthenus var. leucotica Brandt [J. F.] 1853: 320; Type locality: Nishnij-Novgorod, Russia. No types known. Acipenser (Sterletus) kankreni Duméril [A. H. A.] (ex Valenciennes) 1870: 256; Type locality: Probably Russia. Holotype (unique): MNHN 0000-5173. Acipenser (Sterletus) lovetzkyi Duméril [A. H. A.] 1870: 254; Type locality: Russia. Syntypes: MNHN 0000-5171 (2). Sterledus ruthenus var. sibiricus Dybowski [B. N.] 1874: 394; Type locality: Middle and lower Angara River, Siberia, Russia. Syntypes: whereabouts unknown. Acipenser ruthenus rutzskyi Johansen [B. G.] 1946: 171; Type locality: Upper Ob River, Siberia, Russia. Syntypes: (21). Common name: Pr: Sterliyad, Mahi-ye kaviar, En: Sterlet. Diagnosis: Back and flanks are beige. Ventral and laterals are very light-colored, nearly white. Narrow and pointed snout with four long and fringed barbels. Inferior lip with clearly slit. Can be diagnosed from congeners in Europe by having 56–71 lateral scutes, first dorsal scutes not fused with head, barbels fimbriate, lower lip interrupted in middle and 11–27 gill rakers. Meristic characters: D: 27–28, A: 14–18, GR: 11–27, DS: 12–17, LSC: 57–71, VS: 10–19. Distribution: Caspian Sea basin (Fig. 23). Naseka and Bogutskaya (2009) reported from middle and southern Caspian Sea but never confirmed by specimens of 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. Taxonomy. Conservation: IUCN: Vulnerable A2cde (Gessner et al. 2010b).

Published as part of Jouladeh-Roudbar, Arash, Ghanavi, Hamid Reza & Doadrio, Ignacio, 2020, Ichthyofauna From Iranian Freshwater: Annotated Checklist, Diagnosis, Taxonomy, Distribution and Conservation Assessment, pp. 1-14 in Zoological Studies 59 (21) on pages 16-17, DOI: 10.6620/ZS.2020.59-21, http://zenodo.org/record/12822787