Sea urchins have teeth, and they ingest food by grabbing and pulling. Sea urchin is a kind of marine creature that we are very familiar with. It is round like a thorny ball. People who are familiar with it should know that the first step in processing sea urchin is to remove its mouth and teeth, because this part is not edible. Yes, but its teeth are different from what we imagined.
Scientific researchers like to call the sea urchin's mouth a mouthpart, or Aristotle's lantern. It's actually very simple to find the sea urchin's mouth. We just need to look at the only place without spines on this little spiny ball, and that's its mouth. Although it looks like a small hole, the structure of the teeth inside is not simple. The main structure of Aristotle's lantern is five sword-shaped vertebrae and five calcium carbonate teeth. There are specialized muscles between each tooth to control movement, so that once the sea urchin finds food, it can eat it by pulling, scraping, grabbing, etc.
Each tooth of a sea urchin has an independent jaw, which means they can bite freely without being restrained. There is something similar to a tongue next to it. If you look closely, you might think it is an alien creature from the movie. Sea urchins are very typical omnivores. Their favorite food is algae on rocky corals, or some small fish and shrimps, biological detritus, decomposable food, etc. Sea urchins use horny tubes or spines to collect food around them that they can eat, and then use fiber hairs to deliver it to their mouths.
Most sea urchins live in shallow waters of the ocean, and especially like to hide on rocky or sandy sea bottoms. The specific requirements vary from species to species. Sea urchins belong to the class Echinodermata. Statistics show that there are more than 100 species of sea urchins and more than 7,000 fossils known in China. Because sea urchins are the earliest biological models in the history of biological science, they have aroused the interest of many scientific researchers, especially for the early development of eggs and embryos, which play a very important role in this field.