Stenodus leucichthys (Güldenstädt, 1772)
Sheefish
Stenodus leucichthys
photo by Hillen, B.

Family:  Salmonidae (Salmonids), subfamily: Coregoninae
Max. size:  150 cm TL (male/unsexed); max.weight: 40 kg; max. reported age: 22 years
Environment:  demersal; freshwater; brackish; marine; depth range - 10 m, anadromous
Distribution:  North America: Arctic drainages from Anderson River in Northwest Territories, Canada to Kuskokwim River (Bering Sea tributary) in Alaska. Upstream in Mackenzie River and Yukon River drainages to British Columbia, Canada (Ref. 5723). Eurasia: Caspian Sea (common in central and southern Caspian in summer), Volga, Ural and Terak drainages (Ref. 59043). Hybridization with Coregonus nelsoni, Coregonus autumnalis and Coregonus muksun are due more to the broadcasting of eggs and sperm rather than pairing between species or genera (Ref. 27547).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 11-19; Anal spines: 0-0; Anal soft rays: 14-19; Vertebrae: 63-69. Distinguished by its large mouth, the protruding lower jaw, and the presence of only 13 to 17 gill rakers on the lower limb of the first gill arch (Ref. 27547). Dorsal fin high and pointed; pelvic fins with well developed axillary process (Ref. 27547). Generally silvery, with the back usually rather green, blue or pale brown; silvery white below; dorsal and caudal fins have dusky margins, other fins pale (Ref. 27547).
Biology:  Nerito-pelagic (Ref. 58426). Occurs in coastal brackish waters near mouths of rivers, but usually in rivers or some land-locked lakes (Ref. 4779). At the sea, it is found throughout basin in pelagic zone with temperatures below 18° C and 20-50 m deep (Ref. 59043). Juveniles and adult overwinter and forage at the sea. Encountered in large lowland rivers during migration (Ref. 59043). Adults feed mostly on small fishes; young eat aquatic insect larvae and planktonic crustaceans (Ref. 4779). During spawning migration, it feeds little if at all (Ref. 27547). Spawns on gravel shallows (Ref. 59043). Flesh is white, sweet and slightly oily (Ref. 27547). Sold fresh or frozen.
IUCN Red List Status: Extinct in the Wild (EW); Date assessed: 01 January 2008 Ref. (130435)
Threat to humans:  harmless


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