Hi, the divers are all concerned with IFdiving!
Don't be fooled by the thorny appearance of sea urchins, these invertebrates are an important part of the ecological environment
© RYAN ATKINSON
Are you interested in learning about sea urchins? What, not interested?!
The thorny bodies, slow pace and monotonous colours of sea urchins really don't make them the most charismatic creatures of the ocean. But if you don't understand it at all, how can you discuss likes and dislikes? Please be patient and take a look at the introduction below, maybe after reading it, your understanding and feelings about sea urchins will be greatly improved!
First, the sea urchin is an echinoderm that, like starfish, snaketails, and sea cucumbers, belongs to the marine invertebrate phylum. Echinoderms are characterized by a five-point radiative symmetry of the body and a system of water pipes. The water pipe system consists of a series of small pins that stiffen when water is pushed in, allowing the animal's feet to rotate like a conveyor belt. They often have tough, prickly surfaces, hence their name (in Greek, echinos means "thorn" and derma means "skin"). Of course, the spiny appearance of sea urchins is more prominent than other echinoderms, but if you look closely at the skin of sea cucumbers or starfish, you will find that there are also obvious bumps on it.
© DIEGO DELSO
Sea urchins are further classified as sea urchins, which include the classic "sea urchin" in the picture above, as well as sand money and the sea urchin.
There are more than 900 species of sea urchins worldwide, spread over a wide area from shallow to deep sea. Sea urchins live at depths of up to 7,300 meters. They have a hard outer skeleton underneath their spine, known as the "sea urchin shell". If you've ever seen a purple, white, or green round shell with spots all over it while strolling on the beach, it's most likely a sea urchin shell. Each raised point represents where the sea urchin once attached to the spine when it survived.
© ANDREW BAILLIE
Sea urchins also possess hard mouthparts, which are called "Aristotle lanterns". It is named after the philosopher Aristotle, who, in his book The History of Animals, described the mouthpiece of the sea urchin as a "horned lantern." The sea urchin has five calcium carbonate teeth in its mouthparts, which can be ground and eaten by algae, plankton and kelp.
Sea urchins also play an important role in ecosystems. They are herbivores that control the number of algae and are a favorite food source for many marine life. If the number of sea urchins is unstable, a catastrophic situation can occur. For example, in the 1980s, the Caribbean region's black sea urchin (Diadema antillarum) died in large numbers. Losing their natural enemies, algae began to multiply in large numbers, making it difficult for corals to get the light they needed to grow, which in turn caused a series of ecological problems.
"Don't judge people by their appearance", and the same should be true for sea urchins. As an important member of the ecological environment, although the sea urchin is not proud, it has an irreplaceable role and effect. They're worth a stop and a closer look!