Over all color gr eyish to light blue. Eye yellow.Three greenish-brown blotches on nape and at firstdorsal fin base and two at second dorsal fin base. Peritoneumdark brown to black. Two canine teeth on lowerjaw symphysis. Upper jaw teeth conical. Scales minute,cycloid and embedded. Upper arm rakers long andpointed, lower arm rakers less developed, when appressed,touches adjacent one. Gut very elongate andcoiled. Male with a higher dorsal fin and larger canineteeth than female. On mud flats in streams, under andabove tidal influence, both sexes construct U-shapedburrows in sand to a depth of 1 m. Active in 13-40°Cwith daily variations up to 20°C. Maximum total length24 cm and weight 35 g. Spawning in June. Maturity at80 mm total length. Spawning occurs twice each yearduring April-May and July-September in marine environment.Males territorial. Absolute fecundity up to4900 eggs with a diameter of 1 mm. Food include diatoms,algae, insects, crustaceans and fish eggs.