morphological character
The body length is oval, the side is flat, and the tail stalk is long and narrow. Both eyes are located on the right side of the head, and the upper eye is located on the median line of the edge of the head. The mouth is large, anterior and symmetrical. Most of the eyes are covered with weak comb scales, and sometimes mixed with round scales. No round scales on the eye side. The lateral line is almost straight. The dorsal fin starts from the eyeless side. The pectoral fin with eyes is longer. The caudal fin is truncated.