What kind of animal is a sea cucumber?

Sea cucumber is a sea cucumber belonging to sea cucumber, which lives up to 8000 meters by the sea. It has a history of more than 600 million years. It feeds on undersea algae and plankton, and its whole body is covered with flesh spines, which is widely distributed in the oceans of the world. There are many species of sea cucumbers along the coast of the South China Sea. There are about 20 species of sea cucumbers to eat, which are as famous as ginseng, bird's nest and shark fin.

Sea cucumber body is cylindrical, 10-20 cm long, extra-large up to 30 cm, dark color, succulent thorns. Tentacle wheel shape, 1730, usually 20. The touch and the handcup are well developed. Sea cucumbers thrive on the earth earlier than primitive fish and began to exist in the Precambrian about 600 million years ago. it is the earliest living species and is known as a living fossil of the ocean. He has survived several times of great destruction of the earth and witnessed the changes of the earth several times.

The mouth of the sea cucumber is at the front, mostly on the ventral side, the anus on the back, and more on the back. There are generally verrucous feet on the back and tube feet on the ventral side. The endoskeleton degenerated into tiny bone fragments. Many kinds have 5 rows of canal feet from mouth to anus. The anal foramen is also responsible for breathing and excreting waste. There are 10 or more retractable tentacles around the mouth for predation or burrowing. Many species can release internal organs from the anus and then regenerate new ones, possibly to escape the enemy. There are often cryptofish symbiosis in the cloaca, and there are many toxins that can be deadly to small animals, but not life-threatening to human beings.

The fecundity of sea cucumbers is quite amazing. in order to ensure that the species will not be exterminated, sea cucumbers have super reproductive ability in the long-term process of natural selection and evolution. The first adult sea cucumbers of more than 4 years can ovulate about 5 million eggs at a time in the spring breeding period. In this way, even if there is a 1/10000 survival rate, the continuation of the race can be ensured.

Sea cucumbers are distributed in the United States, Alaska, Japan, Iceland and China. When the water temperature reaches 20 ℃, the sea cucumbers will be transferred to the deep-sea reef crevices or hidden in the rock bottom, do not eat, the whole body shrinks and hardens like a thorn ball, the general animal will not eat it, a sleep is a summer, and only wakes up after autumn to resume activity.

Sea cucumber is not only a precious food, but also a valuable medicine. According to the "Compendium of Materia Medica" records: sea cucumber, taste sweet and salty, tonifying the kidney, tonifying the essence, taking urine, strengthening yang to treat impotence, its sexual warming, foot enemy ginseng, hence the name sea cucumber. Sea cucumbers have the functions of improving memory, delaying gonadal aging, preventing arteriosclerosis and anti-tumor. With the popularization of the knowledge of the value of sea cucumbers, sea cucumbers gradually enter the dining table of the people.