a sea urchin is a marine organism that generally lives in shallow waters. From the appearance, their shape is spherical or similar to the shape of the heart, their color is black. Their shells are very strong and have black spines on them. Although they are not like animals, they are actually animals at heart, belonging to the phylum Echinodermata. They are omnivorous in the ocean and can be found around plants such as algae; It can also eat animals, such as worms, hydras and so on. They generally have chewers in their mouths, which are relatively developed and can be used to chew food. They also have digestive tubes, which are longer and can be used to digest food.
In the marine ecosystem, sea urchins can play a very important role. Sea urchins are still edible, they taste very delicious, and the nutritional value is particularly high.
As mentioned above, sea urchins live in the ocean. Although they do not look like animals, they are actually animals, not plants. In fact, the sea urchin is a very ancient animal in the ocean, the existence of a very long history, also known as "sea hedgehog", "thorn pot" and so on. According to scientific research, sea urchins are closely related to some marine organisms, such as starfish, sea cucumbers and so on. In terms of specific classification, sea urchins belong to the phylum Echinodermata, which is a kind of echinoderm. Echinoderms are invertebrates, and sea urchins are also invertebrates.
Sea urchins themselves contain many species. There are more than 20 orders and hundreds of species in the classification. They all belong to echinoderms. Generally speaking, they are distributed all over the world and have a very wide distribution range.
