How do intestinal comen animals move? 5

The locomotion modes of intestinal comen animals include the following:

1.Flipping bucket movement: Sometimes it is done by bending the body and tentacles and attaching to the base plate alternately.

2.Contraction movement: The myofibrils of the jellyfish form a thin layer of muscle ring on the lower umbrella surface and the umbrella edge, some are separated into sheets by the spokes, and their fibers have horizontal stripes, and they do regular contraction to make the umbrella surface have a rhythmic contraction movement.

3.Vertical movement: The vertical movement of jellyfish can be seen more clearly in jellyfish with bordered membranes. Once the muscles stop contracting, the jellyfish will sink naturally. Its horizontal movement is mostly passive, mostly driven by water and wind.

Take polyps. For example, when the environment is unfavorable, it can leave the original fixed point and drift, and the movement mode is a measurement movement, or an inchworm.

Crawling. It can also be used for somersault exercises, which generally tend to be places with moderate light, sufficient oxygen and abundant food.

What are the movements of coelenterate hydra are (coelenterates have no organs).

8 rows of longitudinal knots on the body surface.

Details: Cnidarians are rarely able to do active displacement movements, and their ability to move is very limited, especially in the hydra type. Movement is caused by the contraction of myofibrils in epidermal muscle cells.

For example, the body of the hydra can do telescopic movements, the body length can reach 15 20 mm when stretching, and the body length is only when contracting, this expansion and contraction is explosive, every 5 10 minutes or so, it is mainly caused by the contraction of the longitudinal myofibrils of the integument muscle cells. Contraction of myofibrils on one side of the body can cause bending of the body. Sometimes it is done by bending the body and tentacles and attaching to the base plate alternately.

The mucocytes at the base can secrete a large number of bubbles, which can cause the polyp to float briefly on the surface of the water. For example, the myofibrils of jellyfish and coral have been separated from epidermal cells to form an independent layer of muscle fibers, for example, the myofibrils of jellyfish form a thin layer of muscle ring on the lower umbrella surface and the umbrella edge, and some are separated into sheets by the spokes, and their fibers have horizontal stripes, and they do regular contraction, so that the umbrella surface has a rhythmic contraction movement.

Coelenterates are taxonomically inferior metazoans, all of which live in water, and are a type of multicellular animals with a relatively simple structure. Coelenterates have two special types of cells, one called intercellular cells and the other called stinging cells. Mesocytes can change to form other cells such as muscle cells, nerve cells, etc.

A stinging cell is a type of cell that can release spikes, which have the function of hunting prey and defending against predators. Because the cnidarian cell is unique to coelenterates, it is found all over the body surface, and there are many tentacles, so coelenterates are also called cnidarians.

The body of a coelenterate is composed of endoderm and ectoderm, so named because the cavity enclosed by the endoderm has the function of digestion and water circulation. Coelenterates are true two-germ multicellular animals, which occupy an important position in the history of animal evolution, and all higher multicellular animals are believed to have evolved and developed through this two-germ structure. It has only one orifice to communicate with the outside world, and it is through this orifice that food and excretion enter and exit.

Common coelenterates are jellyfish, anemones, corals, etc. Sea anemones are generally monomeric, have no bones, and have a cylindrical body. There is a mouth at one end, which is in the shape of a slit, and there are several circles of tentacles in the surrounding part; The other end is attached to a rock or other object in the sea.

It is named because it resembles a sunflower. It uses the stinging cells on its tentacles to paralyze the fish, but anemone fish often swim among the anemones and don't care about that, because their ** secretes a protective mucus that keeps them unhindered in the anemone bushes. In addition to attaching to rocky reefs, sea anemones also attach to the shells of hermit crabs.

In this way, the hermit crab wanders around, causing the anemone to move with it, expanding its foraging range. For hermit crabs, one can be camouflaged with anemones; Second, because the sea anemone can secrete venom, it can kill the natural enemies of the hermit crab, so that both the sea anemone and the hermit crab can benefit.

Although sea anemones can live peacefully with other animals, they often fight with their own kind for territory and food, and there are often scenes of fighting where one party sweeps the wart on the surface of the other's body or pulls out the tentacles. Therefore, there are often many cases of cannibalism among them.

Coral is a kind of coelenterate that lives in the warm ocean, and it is home to the crystal clear jellyfish that live a wandering life in the ocean, and the sea anemone, which is known as the "chrysanthemum of the sea". However, for quite some time in the past, people have been thinking of corals as plants, calling them "coral trees" and beautiful coral reefs as colorful gardens. This is due to its bright and bright colours, bush-like appearance, and even black slugs and snails inhabited by it.

But in fact, they are authentic animals, and they belong to the same class of flowers and insects as coelenterates like sea anemones. Every year, new corals grow on the carcasses of the dead corals, and the cycle continues, and soon a large coral reef is formed.

Although coral reefs do not occupy enough of the world's oceans, more than 1 in 4 known marine fish depend on coral reefs for their livelihoods, and they live interdependent lives with each other.

There are three classes of the phylum Cnidarians, which are classified according to the following:

1.A species has only polyps and no jellyfish in one generation, such as corals.

2.A species has only jellyfish bodies and no polyps in one generation, such as the moon jellyfish.

3.A species has both polyps and jellyfish bodies in one generation, such as peach blossom jellyfish.

Thus, in the class Hydra, polyps and jellyfish are two forms of the same species in different stages of growth.