Sea cucumbers belong to invertebrates, echinoderms and sea cucumbers. There are more than 900 species in the world, and about 140 species in China. Among them, the Indian Ocean and the Western Pacific Ocean are the regions with the largest variety and resources of sea cucumbers in the world. China sea cucumber is distributed in temperate zone and tropical zone, and the temperate zone is mainly in Bo Huang sea area. The main economic variety is Stichopus japonicus, which is also the most famous sea cucumber variety in China.
Introduction of sea cucumber
Xisha Islands, Nansha Islands and Hainan Island are the main producing areas of tropical sea cucumbers in China. The shape of sea cucumber tentacles is an important basis for classification, and dendritic tentacles are found in cladocera sea cucumbers. Shield tentacles are found in cladocera and finfoot sea cucumbers, feather tentacles are found in Anpoda sea cucumbers, and finger tentacles are found in bubble-footed sea cucumbers.
The number of tentacles of sea cucumber is often 10, 15, 20, 25 or 30, all multiples of 5, but there are also 12. The endoskeleton of sea cucumber is underdeveloped, and there are many tiny calcareous bone fragments buried under the skin that must be seen with a microscope, and the number is generally large.
To observe the bone fragments, we need to do some processing. The simplest method is to take a small piece of skin, put it on a glass slide, and then drop 1-2 drops of sodium hypochlorite solution on the skin for 1-2 minutes. Sodium hypochlorite solution will corrode skin tissue. Add 1-2 drops of distilled water, cover the glass slide, and put it under the microscope, and the residual bone fragments can be clearly observed.