One of the most well-known representatives of polychaete worms is the marine grit. This aquatic animal, having the Latin name Arenicola marina, belongs to the sandbill family of the order Capitellida.
You can meet the sandbags on the sandy beaches. The name of the animal itself indicates that its habitat is sandy soil. In some places, sandguns come in large numbers.Sandblast (Arenicola marina).
What does the sandbox look like?
These are quite large worms. In length, they grow about 25 centimeters, in diameter - about 1 centimeter. The color of the marine sandblast can be varied: yellowish, reddish and greenish. The body of this worm consists of three sections: thorax, abdomain and tail.Peskozhil next to his hole.
The "head" part of the body has a reddish-brown tint, there are no tentacles and bristles on it. The middle part of the body is red. Setae and a pair of cirrus gills are located on it on its sides. The sea sandblast has a developed circulatory system, and its blood is saturated with hemoglobin.
Where do the sand dwellers live?Sandbags are multi-bristle worms that live in the sand.
These polychaete worms are found in the Black Sea, as well as in the Barents and White Seas. In places where sand dwellers massively settle, whole "sandy beaches" are formed, so their colonies are dense in number.
The lifestyle and nutrition of the sand dune
This type of animal in its behavior reminds everyone of the famous earthworms. Sandworms swallow sea sand and pass it through themselves, thus obtaining nutrients (mainly rotting algae). Researchers estimate that about 16,000 kilograms of sand pass through themselves on a hectare of coast per day!Sandworms process 16 tons of sand.
These unusual creatures live in a hole that they themselves build. Each sandblast specimen has special glands that secrete a mucous sticky substance. Thanks to him, the sandblast glues sand grains or plant particles passed through it, which eventually become the walls of the "tube-shaped house" (sand-hole burrows).Sandbird colonies form sandy beaches.
Mink peskozhil - this is not only his home, but also his reliable refuge from enemies. If the worm suddenly sees a big-eyed fish and tries to grab it, then the peskozhil tightly "cuts" with bristles into the walls of its tunnel and tries to save at least part of itself. The second half remains in the fish’s mouth, but this is not a problem for the sand dweller - after a while the “tail” will grow back anyway. In addition to fish, gulls (and other seabirds), echinoderms, and various crustaceans feed on sandguns.
Despite the constant danger of being eaten, sandbats are not in danger of extermination, because these animals are very fertile. About 1,000,000 eggs develop in the cavity of the body of a female sand gut alone.
Sandbags: value for peoplePeskozhily - a source of valuable medications.
These representatives of polychaete worms are often used as bait for fish during fishing.
In addition to the fishing industry, they learned to use peskozhil in medicine: from the tissues of these worms, scientists made an extract and obtained a substance with a broad antimicrobial effect.