Body silver y with numer ous, small, br ownto black spots on head, flank and dorsal and anal fins.Peritoneum dark brown to black. All fins with somespeckling on rays and membranes. Head length greaterthan dorsal fin spine length. Scales on belly in front ofpelvic fins small. Gill rakers reaching second adjacentraker when appressed. Last dorsal fin unbranched rayvery strong, but narrows distally and bears large serrationson three-quarters of its length. Snout with a depressionin front of nostrils. Mouth straight to a gentlearch. Tubercles between eyes, around snout and on topof head, in males. In habitats with temperatures up to29°C, EC up to 1353, DO 6.1-11.7 mg/l and pH=6.4-6.8. Maximum total length 40 cm. Reproduction inApril-June on gravel beds. Food include algae andaquatic insects.