Coral and zooxanthellae are related. Coral provides a good living environment for zooxanthellae, which provides energy for coral through photosynthesis. It is because of the existence of zooxanthellae that healthy corals are colorful.

Coral is a marine cylindrical coelenterate. Food enters through the mouth and residue is discharged through the mouth. It lives on tiny plankton in the ocean. It has more than eight tentacles, and there is a mouth in the center of the tentacles. It is a social animal. Coral can absorb calcium and carbon dioxide from seawater, and then secrete limestone to become its own living shell. Coral is the secretion of coral and constitutes the supporting structure of coral.

Coral polyps are very small, and there are many small tentacles around their mouths, which are used to catch tiny creatures in the ocean. They can absorb minerals from seawater to build shells to protect their bodies. Coral is just a hydra-shaped individual, hollow and cylindrical, with the lower end attached to the surface of the object and a mouth surrounded by one or more tentacles at the top. Tentacles are used to collect food and can be stretched to a certain extent. It has specialized cells (stinging cells). When the stinging cells are stimulated, they will turn out the stinging silk sac and paralyze their prey with stinging silk.

Coral, soft coral, horny coral and blue coral all live in groups. Each hydra in the population has eight tentacles, and there are eight diaphragms in the gastric circulation cavity, of which six diaphragms have cilia for introducing water into the gastric circulation cavity, and the other two diaphragms have cilia for guiding water out of the gastric circulation cavity. Bones are endoskeletons. Living corals are the rarest. They are corals that grow on dead corals.

About zooxanthellae:

Chrysophyta is a unicellular algae with a very small volume and a diameter of only microns. According to statistics, there are 30,000 insect yellow algae in every cubic millimeter of coral. Most of them are autotrophs, which will provide the host with translocation-type reduced carbides, such as glucose, glycerol, amino acids and other products of photosynthesis, among which up to 90% of the energy of corals is provided by zooxanthellae.

Other biotypes of zooxanthellae:

1. Insect yellow algae, jellyfish. Chaotian jellyfish Chaotian jellyfish is a member of the genus Andromeda. They obtain algae (such as zooxanthellae) by eating algae or corals (such as zooxanthellae). They arranged algae in transparent antennae. In the process of photosynthesis, they will extend their tentacles upward to maximize the sunlight exposure area.

2. Worm yellow algae. Manjianghong is a large bivalve shellfish. Insect yellow algae can make full use of the convenient conditions provided by the mantle to reproduce, such as space, light and phosphorus, nitrogen and carbon dioxide in metabolites; You can use zooxanthellae as food.