black carp (Pneumatophorus japonicus), perciformes, mackerel, mackerel. The body is thick, spindle-shaped, and the tail handle is strong; There are two longitudinal ridges on each side of the caudal fin base.

The body is thick, slightly flat and spindle-shaped. Generally, it is 2-4cm long and weighs 15-4g. The head is big, the front end is tapered, the eyes are big and high, the mouth is big, the upper and lower jaws are the same length, each with a row of fine teeth, and the plough bone and hipbone have teeth. The body is covered with small round scales, the back of the body is bluish black or dark blue, and there are irregular dark blue insect etches above the horizontal line of the pectoral fins on both sides of the body. The abdomen is white and slightly yellow. There are 2 dorsal fins, which are far apart. The first dorsal fin has 9-1 spines, the second dorsal fin is opposite to the gluteal fin, and there are 5 small fins in the back. The caudal fin is deeply forked, and there are two raised ridges on both sides of the base; The pectoral fin is light black, the anal fin is light pink, and the other fins are light yellow.