A ventr al tr ansver se mouth. Snout r elativelyelongated, semi-conical and sharp. Four fringed cylindricalbarbels under the middle of snout which extend backto the mouth. Lower lip continuous with a groove. Fiverows of scutes not interspersed by smaller starry scutes.The first dorsal scute large. Scutes lack a hook. Ventralscutes lost or absorbed in large adults. Gill membranesjoined to the isthmus. Small spiracles present. Caudalpeduncle semi-conical. Heterocercal caudal fin. Posteriorlypositioned pelvic fins. Freshwater and anadromous.Benthic, on muddy bottoms up to 50 m depth. Preferscolder waters (6-13°C in spring and 12-18°C in fall).Maximum age 43 years, total length 214 cm and weight127 kg. Females larger than males. Males mature at 9-13years and females at 13-16 years. Minimum spawningintervals 2 years. Spawning migration in spring (April-May) and fall (late September-early November), mostlyat river openings. Eggs laid on gravel or stone beds at 4-25 m depths, at 9-15°C. Absolute fecundity up to1,650,000 brownish-grey and ovate eggs of up to 3 mmin diameter. Mostly solitary fish. Food include aquaticinsects in juveniles, and crabs and small fish in adults.Halt feeding in spawning season.