What kind of food do sea urchins eat?

Sea urchins are a kind of invertebrates living in marine shallow waters, which are mainly characterized by spherical, disc-shaped or heart-shaped bodies, no wrists, endoskeletons heal each other to form a strong shell, and most species have complex chewers in the mouth. it can be divided into two subclasses: regular and irregular sea urchins, with a total of more than 900 species, mostly concentrated on the rocky or sandy seafloor in the coastal zone. Let's take a look at what kind of food sea urchins eat.

What kind of food do sea urchins eat?

Sea urchins eat a wide range of food, can be carnivorous, and feed on gastropods and other echinoderms. It can also be herbivorous, feeding on all kinds of seaweed. The types of soft seafloor and irregular sea urchins mainly feed on organic debris, collect the surrounding organic particles through tube feet or thorns, and then send them to the entrance by cilia. The mouth is located in the center of the perioral membrane (irregular sea urchins may be located in the front of the body). There is a complex feeding structure in the mouth, that is, a square lamp-shaped structure connected by a series of bone plates, teeth and muscles. used to cut and chew food.

Where are sea urchins distributed?

Sea urchins live in the world's oceans, of which the Indian Ocean and the western Pacific Ocean have the most species, from shallow water to 7000 meters of deep water. Most sea urchins like to live in rocks, coral reefs and hard seafloors, mainly on tube feet and thorns, which are often associated with feeding. When there is plenty of food around, it rarely moves, only a few centimeters a day. Usually lurking in cracks or depressions. Irregular sea urchins mostly live in the sand and move mainly by needling in the acupoints or on the sand surface.

What kinds of sea urchins do you have?

1. Horse dung sea urchin: the shell of horse dung sea urchin is strong, hemispherical, with a diameter of 30mm to 40mm, up to a maximum of 60mm. The reverse mouth is low, slightly raised and flat. The width of the stride zone is equal to that of the interstride zone, but the swelling degree of the interstride zone is slightly higher than that of the stride zone, so the shell shape is a smooth regular Pentagon close to a circle. It is generally considered to be a herbivore, generally feeding on brown algae, red algae and green algae, mainly living in shallow reefs, gravel, sand and other seafloor.

2. Spiny-crowned sea urchins: the diameter of spiny-crowned sea urchins is 70-80 mm, and its height is slightly larger than the shell radius. The shell is thin and low hemispherical. The large spines on the reverse mouth are slender like needles, hollow, with ring wheels on the surface, with a length of about 3 to 5 times the diameter of the shell, up to 26 cm in length. Life is all purple and black, and the color of big spines often changes. The spine is very sharp and thin, and after piercing into the skin, it is broken in the human body, causing severe pain.

3. Heart-shaped sea urchins: heart-shaped sea urchins are usually oval or heart-shaped, with brittle shells and 4 walking zones. The body surface is covered with short thorns. Living in a hole with mucus on the inner wall. Tube foot length, extended to the sand to catch small food particles, some tube foot breathing and sensory function. To move by the act of stinging. Digging is constantly being done in the deep sediment of the sea floor, moving slowly under the sediment, collecting food particles with pipe feet.

4. Ribbed sea urchin: the shell of the ribbed sea urchin is thick and strong, and its shape changes greatly. The stripe is slightly raised, and the width is about 2 / 3 of the interstride. There are large and conspicuous triangular dents on the horizontal suture lines of the strips above the equator, and the holes of the tube feet are arranged in an arc every 3 pairs. Each step of the equatorial department has a large wart, a middle wart and many small warts.