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Nereid, sea worm: description

In the world there is a huge variety of worms. They live on the ground, underground, and even in the depths of the sea. Not always these representatives of the fauna cause positive emotions in the people watching them, mostly people are dislike for this species. Today we decided to devote an article to one of the representatives of annelids, this is a nereid - a sea worm. We will try to talk about it as much as possible, describe the appearance and life.

Nereid - worm: description of appearance

Where does this species live? At the bottom of the sea live Nereids. These are not those who are called daughters of the king of the sea in ancient Greek mythology. These are ordinary worms. The polychaete worm of Nereid belongs to the ringed worm . His body consists of many rings, as we all have a known earthworm.

Nereid is a worm with a serpentine body structure. He has a head, metameria (trunk), anal lobe and lobate-like limbs.

On the head of the Nereid there are eyes - as many as two pairs. Also on the head part of the worm there are tentacles, two-segment palms.

The limbs of the Nereid are dotted with a multitude of bristles (hence the species - polychaete), with which it easily navigates the bottom of the sea on a good speed for the worm.

Metamerism is a repetitive, absolutely identical part of the body. In our case, these are rings. Nereid is a worm with a specially developed musculature. He can easily dig in the bottom of the bottom to hide from danger, or lay eggs.

Nereid is quite small, it rarely reaches four centimeters in length, mainly its growth - two or three centimeters. But they are found in fresh waters and individuals up to 90 centimeters! Such a "monster" can be found in the freshened waters of Japan. It is called green non-Rise.

Nereid - a worm is usually brown. It can shimmer with green, blue and red hues. A sight, truly, bewitching sight. This worm is beautiful, and absolutely safe for humans. Do not be afraid that he will bite you or decide to live in your body. Nereid with the man lives amicably, and he does not represent for her interest in the quality of food.

Internal structure of the Nereid worm

Muscles in the body of the sea nerve worm form a dermo-muscular sac. This is a structure that does not have an internal cavity. The organs are separated by a loose connective tissue, or parenchyma. Above the body is covered with skin, and under it are several layers of muscles. These muscles are not located in separate bundles, but are tightly fused to the skin. This is the skin-muscular sac.

The intestine of the Nereids consists of three compartments: the middle one is endodermal, and the extreme (anterior and posterior) are ectodermal.

Nereid food

Nereid is an omnivorous worm, but still prefers algae to a meat ration. Its menu includes mollusks, small invertebrates of the seas. These creatures are not dangerous for large and small fish, although they are endowed by nature with powerful jaws with sharp teeth. Also, Nereid will refuse the food of a person who enters the water. So, having met such a creation, do not rush to treat it with sausage or cake, Nereid does not appreciate your menu.

Organic remains on the bottom are also food for this worm. When digging in the ground, the next pit of the Nereid often swallows silt. The organic substances in this sea rock are well absorbed by the body of the worm, and contribute to its vital activity.

Nereid as a link in the food chain

This worm itself is constantly endangered. Enjoying the meat of the Nereid is building up entire lines. The first are fish and large shellfish. They are constantly hunting for an innocent neighbor.

Also during the low tide the Nereids remain defenseless. The remaining worms are excellent food for gulls. These swallows are ready to wait for hours, when the water leaves, to eat fish, shellfish and sea worms.

So it turns out that the predatory Nereid herself becomes the object of a diet for many representatives of the sea and land. The worm is not endowed by nature with protection, such as big fangs, poison, or an unpleasant odor, so every hungry representative of the fauna can freely eat it.

How do worms breathe?

The Nereid, like the earthworm, breathes through the entire surface of the body. If the raining representative of the family crawls to the surface from the wet earth to breathe, then how does the Nereid dies in the water?

In many marine worms, including the heroine of our article, on the blades there are processes in the form of gills. In these very gills, there are many blood vessels. Blood is enriched with oxygen, which has been dissolved in seawater, through the same gills gets rid of carbon dioxide.

Thus, Nereid can spend a long time both in water and on land. Nature took care of its creation, giving it two ways of breathing.

How does the sea worm multiply?

Many worms are asexual, and multiply by division. Nereids have both male and female sex. Fertilization occurs in the external environment.

When worms reach sexual maturity, and the breeding season begins, they rise from the bottom closer to the surface of the water. They grow new bristles that allow you to swim and rise to the surface.

The bodies of males and females begin to drastically change shape, color. You might think that at this moment they are turned inside out, and they are suffering greatly from the pain, but this is far from being the case.

After a while, ruptures appear in the bodies of the Nereids, from which the sexual cells exit into the water. Mom and Dad, after the cells for reproduction have been released into the water, perish.

After the fertilization, eggs start to grow. Later on, tiny larvae appear in the world - babies of Nereid. At this moment they are exposed to great danger: even small, but predatory mollusks strive to catch and eat babies.

Where do the Nereids live?

Not in all the depths of the sea you can find such a polychaete worm. They live in the coastal zones of the Caspian and Azov seas, as well as in the waters of India. It is rare to be found in desalinated waters, mainly in the zone of Japan.

Nereids do not live separately, they live, creating dense settlements. Water for their life should be comfortable warm temperature.

So we got acquainted with this representative and the inhabitant of the seabed. There is nothing terrible in Nereid, she is afraid of all!

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