Speartail fish

The only species in the cervical ratchet spearfish species is the only living total fin fish.

the body is a long shuttle shape, the body is bold, the body is about 1.5 meters long. Big head, wide mouth, sharp teeth. The skull has special intercranial joints. There is a pair of large throat plates between the head and jaw. The body is covered with large and thin oval scales, the scales reveal parts with many small crucibles or warts, so the body surface is rough, the back of the body and fin base scales are small. Sideline completely. Dorsal fin 2: the first dorsal fin is bone-strength, with a crucible, ratchet-like, and the second dorsal fin is similar in shape to the pectoral fin, abdominal fin and hip fin, and the fins are born on a very thick meaty fin handle. The bones in the fins are arranged in sections that are not symmetrical. The tail fin is approximately spear-like in shape, with 3 leaves, and a central leaf splits the entire tail fin equally between the upper and lower parts. The spine is present for life, with small pieces of hard bones on and below it. The intestine has spiral flaps.small, no breathing function, only to regulate the proportion of fish in the water. The egg is born. For carnivorable fish. In December 1938, the first was captured in the deep sea off the island of East London on the south-east coast of Africa, and it was not until 1952 that the second was captured near the Comoros Islands in Africa. Since then, hundreds of them have been caught in the region.

species of total finfish have all been extinct on Earth, and spearfish are living fossils that have survived long geological periods and were only understood from fossils in the past. Through the comparative anatomical study of spearfish, it is helpful to explore which species of amphibians evolved in the first place.