Two: Tuna is long and stout, round, streamlined, tapering backwards, with a slender tail base and a forked or crescent tail fin. There are obvious ridges on both sides of the caudal stalk, and a row of small fins behind the dorsal fin and gluteal fin. It is torpedo-shaped with a slightly round cross section. Tuna is also very strange in shape. Its whole body is streamlined, and the breastplate extending along the head seems to be a unique balance plate, which can adjust the water flow. In addition, the tuna's tail is half-moon, which enables it to sprint forward quickly in the sea. Strong muscles, crescent-shaped tail fin, breastplate with gradually expanding scales on the shoulders, dark on the back and silvery white on the ventral side, usually with rainbow-colored light and stripes. Another feature is that there is a well-developed vascular network under the abdomen, which can be used as a thermoregulation device for long-distance slow swimming.
Third, the characteristics of pomfret:
Body shape: short and tall, extremely flat, slightly rhombic, with a body length of about 20 cm.
Head: the head is small and the side is flat and high. The kiss is short, round and blunt, slightly protruding in front of the low collar. Small eyes, lying on your side. The space between the eyes is a big arc-shaped bulge, and the nose is very small, with two on each side. The front nostril is round, the back nostril is fissured, with a small mouth and a slight inclination.
Jaw: The maxilla is located below the front edge of the eye. Each mandible has 1 row of fine teeth, which are closely arranged.
Gills: gill holes are small, gill rakes are short and weak, and they are loosely arranged.
Scales: Scales are small and round and easy to fall off. The lateral line scale is 1 10 ~ 130, and the lateral line is high and almost parallel to the back edge.
Fin: dorsal fin ⅸ ~, I-42 ~ 48, starting slightly in front of the starting point of gluteal fin. Gluteal fin ⅵ ~ ⅶ, I-4 1 ~ 46. The dorsal fin and the gluteal fin have the same shape, the spines of the fins are all cross-shaped, and the front ends of the fins are all raised in a sickle shape. Growth of pectoral fin, 24 ~ 27. No ventral fins. Tail fin 17, with deep bifurcation. The body is silvery white, the upper part is slightly bluish gray, and most scales have tiny black spots.