What are Echinoderms?

Echinodermata is a class of deuterostomes, which has a high evolutionary status among invertebrates. Most are benthic, and a few sea cucumbers are planktonic; free-living species can move slowly. It is widely distributed from shallow seas to thousands of deep seas. There are more than 6,000 existing species, but as many as 20,000 fossils. From the early Cambrian to the entire Paleozoic, it was very prosperous. Five of them were completely extinct. Common starfish, sea urchins, sea cucumbers, sea snake tails, etc., are all echinoderms. They have some unique features in morphology, structure and occurrence, which are very different from the original animals. The appearance is very different, including star shape, spherical shape, cylindrical shape and flower shape. Adult five-radiation symmetry (secondary radiation symmetry) is manifested by the arrangement of tube feet.

The appearance is very different, including star shape, spherical shape, cylindrical shape and flower shape. Adult five-radiation pair

Most are benthic and a few sea cucumber camps live a plankton; free-living species can move slowly. Feeding side

Most of them are male and female, the germ cells are released into the sea to fertilize, the larvae have the same shape when they first occur, and they vary from class to class in the future. A few species can reproduce asexually. Very sensitive to water pollution and regenerative power is generally strong.

Some echinoderms are precious foods, such as sea cucumbers and sea urchin eggs. Within marine ecosystems, echinoderms are often dominant species in certain benthic communities. Echinoderm can account for up to 90% of the benthic biomass on the abyss. In the study of marine animal geography, echinoderms are often a good indicator species. Certain swallowing species can carry large amounts of spoilage substances and reduce the activity of microbes on the sea floor. Certain types of diamonds cause damage to the coastline. Certain snaketails are often used as food by benthic fish. Starfish likes shellfish, which is often an enemy in shellfish farming. There are many kinds of echinoderm fossils, which occupy a certain position in geology. Some limestone formations are made up of decomposed sea lily skeletons. In terms of basic theoretical research such as experimental embryology, sea urchin eggs are one of the best experimental materials. Some echinoderms have venomous glands or venom, which may develop into drugs through research. Sea cucumber and mucopolysaccharide isolated from several sea cucumbers have anticancer activity.