Body compr essed and oblong. Mouth small,toothless and terminal. Gape not extending to eyes. Upperjaw non-protractile. A notch on upper jaw in themid-line into which a lower jaw protuberance fits. Lateralline visible. Scales cycloid but no scales along thebelly. Large eyes with an adipose eyelid. Swim bladderpresent. Gill membranes united but not attached to isthmus.Intestine very long with many folds. Lower part ofesophagus with a gizzard and longitudinal folds. Numerouspyloric caeca. Peritoneum black. Anadromousand prefers warmer waters. Eurythermal and toleratesalinities up to 158‰. Maximum age 12 years, totallength 129 cm and weight 18.6 kg. Maturity at 3-5years. Sex ratio 1male:2.4females. Spawning in May-June on muddy beds at 25-30°C. Absolute fecundity upto 7,300,000 eggs of 1.3 mm in diameter. Ribbon-likelarvae migrate to coastal areas, metamorphose and mayenter estuaries or spread out in deeper waters. Food includesurface scum, fish eggs and larvae and algae.