Distinguished by the following characters: vertebrae (without 4 vertebrae of the Weberian apparatus) not exceeding 37; for fishes with over 15 cm body length, there are 7-9 longitudinal rows of scales between the lateral line and insertion of the ventral fin; body depth 1.7-2.5 in l; length of dorsal spine exceeds that of head, depth of caudal peduncle is as a rule less than its length, width of oral slit is less than two times in head width; corneous sheaths usually thin, on upper jaw appear as a thin crescent (distinct in small specimens), rarer triangular; supraorbitale in small specimens relatively narrow, like a thin crescent, in large specimens it is triangular or trapezoid; the swim bladder is three chambered, the third chamber is usually very reduced; the anterior body outline in adults usually has a clearly seen depression at the level of the end of the head followed by an abruptly ascending "hump", depth of the head at the level of this depression frequently makes up 40% of the greatest body depth. In adults (1>15 cm) on scales in the anterior body sides (including scales of the lateral line and several rows above and below the lateral line) in the posterior (outer) part there is an opaque sector with black dots either all over this sector or only along its posterior margin; the dorsal side very dark, almost black, the sides and belly slightly lighter (Ref. 51498).