Amphioxus - Amphioxus

The boneless fish is a precious animal, scientists discovered that the boneless fish lived about 500 million years ago, and still retain their original character. This is living evidence to study the origin and evolution of invertebrates.

(Photo: biol.paisley)

3-5cm long bone valve fish, very strange morphology. The body is long and flattened, with 2 pointed tips like a shoulder. The whole body is pinkish and transparent, it can be seen clearly that the fibers are arranged vertically in parallel. No scales, finless, invertebrate; The viscera is just a rhythmic, rhythmic tube. There are no senses like eyes, nose, ears. There is no differentiation for digestive gas. In addition to the mouth and throat, the rest is just a segment of the bowel that leads directly to the anus.

Bonefish often follow tidal water to enter the estuarine area where the seabed is shallow, almost defenseless but capable of penetrating into the ground. About 3-4 years old, they often bury themselves half in their sand, the other half going out to pick up plankton from the river.

By the breeding season, the fish bone bones paired one by one from the sand, swimming and mating together. Female males separate, mature sexual cells expose, fertilize in the water. The next morning the fertilized egg became a free-swimming baby fish. Three months later, it became a big fish but the genital system had to mature one year later.

Biologists believe that bone fish is a transitional animal that evolved from invertebrate to vertebrate, an ancestor of fish, but completely non-fish. It has a special place in the evolution of animals.

Structure of Bonefish - Amphioxus (Photo: lander)