Body silver y, back blackish-olive or greenish-grey. Peritoneum silvery to brown. Pelvic axillaryscale present. A scaled keel behind the pelvic fins.Lower jaw tip projects and fits into a notch in upperjaw. Gill membranes narrowly attached to isthmus, almostunder the posterior eye margin. Gill rakers veryshort and club-shaped. Pharyngeal teeth elongate, compressedand hooked. Gut elongate and S-shape. No barbeland tick dorsal spines. Begin to migrate upriver inOctober, peaking at the end of November and the earlyDecember. Overwinter in deep holes, emerging in earlyspring as rivers flood and move to spawning grounds.After spawning, return to the Caspian Sea, but somepopulations reside in Anzali Wetland. Maximum age 8years, total length 58 cm and weight 2.65 kg. Maturitymostly at 4-5 years and minimum 41 cm total lengthand 840 g weight. Spawning season mid-February tolate March at 10-13°C. Spawning non-intermittent andin a short period (10-15 days). Absolute fecundity up to264,250 eggs of up to 1.5 mm in diameter. Young migratedownriver from June to August at age 3-4 monthsand 5-10 cm total length. Food include plankton inyoung, and gobies, silversides and frogs in adults