The amphioxus is dioecious and usually spawns in June to July. Its reproductive glands are attached to the inner wall on both sides of the perigill cavity and are 26 pairs of small, thick-walled rectangular sacs around the periostracum, and the male and female can be identified by the fact that the spermatheca of the amphioxus is white or the ovary appears yellowish when they are sexually mature.
When the amphioxus is in the water, it will bury half of its lower body in the sand, exposing only the front half of its body outside the sand, and it mainly relies on water currents to bring plankton, diatoms, and plants to feed on, and this kind of passive feeding method indicates that it belongs to a very low-level vertebrates.
The amphioxus, as a surviving species of the subphylum Cephalopoda of the phylum Chordata, is a typical living specimen of the transition from invertebrate evolution to vertebrate. Since the discovery of amphioxus by Pallas in 1774, it has been emphasized by the zoological community, and is an extremely valuable model animal for the study of the origin and evolution of vertebrates, including human beings.
The number of amphioxus in the distribution of the world is generally not large, only in the coastal distribution of China, but due to the destruction of the habitat environment and other reasons, the amphioxus resources are declining year by year, the distribution of the area has become more and more narrow, has been reduced to a rare species, China has been listed as the second level of protection of the amphioxus animal.