A small nostril on head. Mouth funnel-like with one or rarely, two teeth on upper and lower oral plates, and 3-6 large blunt teeth on mid-plate. Oral disk narrower than body width. Maximum age 5 years, total length 485 mm, and weight 206 g. Females with a smaller urogenital papilla. During spawning migration, they undergo certain morphological changes, e.g., color changes, teeth become blunt, fin size increases and in males, dorsal fins unite at base, and length of urogenital papilla increases. By decreasing water temperature (15-23°C) and increasing water level, they migrate in schools to Caspian Sea rivers and hide among stones during winter. Spawning begins in early March to early May on gravel and die after spawning. Absolute fecundity up to 51,000 blue-green and ovate eggs of up to 1.2 mm in diameter. After usually 7 months, metamorphosis of ammocoetes occurs in fall, when eyes and teeth grow larger, fins become more distinct and their colors change. Food include detritus and diatoms, in ammocoetes, and amphipods, algae, aquatic vegetation or as scavengers, in adults. Migratory, transforming and spawning lampreys halt feeding.