Over all color gr ey. A ser ies of 8-9 brownishelongate spots or blotches on flanks and back. Belly,lower head and genital papilla pearly white. A dark barfrom eye to lip. A dark spot on first dorsal fin. First dorsalfin with 1-2 rows and second dorsal fin with 1-3 rowsof grey spots in most immature. Breeding males black orblue-black and medial fins with a yellow-orange margin.Top of head and occiput with ctenoid scales. Interorbitalwidth less than eye diameter. Snout longer than eye diameter.First dorsal fin high with first branched ray abouttwice as long as penultimate ray. Pelvic fin small, almostreaching anal fin. Nape with ctenoid scales. In inshorebrackish waters and enters rivers. Over sand, mud andsandy-shelly bottoms. Salinities of up to 47‰ tolerated.Maximum age 4 years and total length 16 cm. Sexualmaturity at 1-2 years and 9-12 cm. Sex ratio equal to1male:1.4females. Spawning from late April to Septemberwith a peak in May at 18-20ºC and 0.5-1.3 m depth.Absolute fecundity up to 1030 yellow eggs with a diameterof 2.1 mm. Eggs laid on or under stones and plants.Male excavates and defends nests. More than one femalelays eggs in a nest. Food include crustaceans, molluscs,polychaetes, chironomids and small fishes.