Biography of worms

Magic biologists of the Moscow State University Biostation of the editorial office may not coincide with the author’s opinion to eat at great depths not easy: food in the world ocean is produced on the surface and gradually settles, but it is “corroded” in the very first meters - it is this zone that is the most productive. Deep-sea residents have to sit on a hungry ration and somehow adapt.

For example, deep -sea polar hungeries, known as sea cucumbers, rarely eat aptly! After a rare satisfying dinner, the ripening of the germ cells starts in holoturia and they are urgently multiplying. Perhaps this was the last meal in their life - it is necessary to have time to reproduce offspring. But the hero of today's story, Echiuride Protobonelius calmly, a little later, imagine this seaworm, was in a more deplorable situation than the sea cucumbers.

She not only lives on the seabed, where it is dark, cold and hungry, but still can’t move around it and spends all her life in the hole that itself and digging itself. Accordingly, she cannot go for food, but she somehow needs to eat ... Perhaps, it's time to present this stoic worm. Echiurids are relatives of the rainworm and its other brothers, ring worms, only their body is not ringing, and the front end of the body is equipped with a long trunk.

I must say that they look very specific-it is not for nothing that one of their representatives in the English-speaking countries nicknamed “Penis Fish” in a scientific one, it is called Urechis Unicuntus. Echiurids settle both in the adhesive zone and at depths of up to seven kilometers.

Choosing a place you like, echiurides begin to dig deep holes in the ground, using their sausage body like a jack of a hammer. An reduced trunk is exposed to the surface of the soil of echiurides, which has the appearance of a long, very reduced tongue and is used to collect food. How exactly the trunk works and how Echiuride has sorting food particles to edible and inedible, is still not very clear.

How do such worms live in the depths of the ocean, how do they eat and how they multiply? Unfortunately, scientists cannot simply immerse sophisticated cameras by five kilometers and shoot the life of echiuris and other deep -sea invertebrates, especially if they live in deep burrows, and it turned out that about 90 percent of the deep -sea population make up such worms.

Here, researchers come to the rescue of modern methods of functional morphology. In short, we explain the essence of these methods. Scientists study the structure of different systems of organs using methods of light and electron microscopy, and also make their full interactive 3D reconstruction. Then they put forward assumptions how these systems work, and then find out how the animal lives with such a set of organs.

Similar methods are used to study the lives of various animals, and finally they were applied to deep -sea echiurides collected in the Pacific at a depth of 5.6 kilometers in the distant year. Small deep-sea echiurides were collected during one of the flights of the Vityaz research vessel using a trawl, which was lowered to a greater depth, dragged along the bottom, and then lifted to the deck along with kilograms of sea soil and animals living in it.

The mass appearance of small bottom worms turned out to be new to science and was described in the year as Protobonellia Zenkevitchi, in honor of the outstanding oceanologist Lev Aleksandrovich Zenkevich, who has been working at the Department of Zoology of invertebrates of Moscow State University for a long time. However, the morphology and anatomy of this species only in the year were examined in detail, using animals collected almost 50 years ago.

The body length of protobonellia does not exceed two centimeters, and the length of the trunk is about eight millimeters. Such body dimensions can be considered very imminent for echiuride: among them are species whose body reaches 30 centimeters in length, and the trunk can stretch 1.5 meters. In total, a worm is obtained long per person! But although the protobonelly is not impressive in their size, with the help of modern microscopy methods, scientists revealed unusual features of their structure.

It turned out that in these worms, the trunk is divided into three parts: a terminal festony tip, the middle flattened part and base. From the inside, the terminal tip is strengthened by cells with large vacuoles, and its surface forms longitudinal grooves with a width of seven to ten microns approximately like human red blood cells. These grooves are lined with cilia, which is very important!

The middle part of the trunk is very muscular, and the base forms a kind of lip covering the mouth. Such an unusual structure of the trunk led marine biologists to the idea that the trunk is located on the ground so that its fortified terminal tip rests on the ground, and the muscular middle part with the arch rises above the ground. The beating of the cilia of the longitudinal grooves of the trunk of the trunk provides the micro -subsidiability of particles of the soil, but only those particles that are suitable in diameter under the width of the ciliary grooves can get to the middle part of the trunk.It turns out that the protobonelli consumes food with the size of seven to ten microns, and if large prey still gets into the trunk, then it still cannot get into the mouth covered with a fold-gear.

Through such a “sieve” only unicellular diatomic algae and dilapidated organic residues pass. It turned out that the intestines of the protobonelly were arranged no less unusual than the trunk. Like other echiurides, the tiny protobonelli are equipped with 11 intestinal departments and it is the intestines laid down by numerous loops that occupies a large part of the body.

Scientists have suggested that thanks to such a complex intestine, worms can be processed as high quality food as well as possible. The 3D reconstructions methods made it possible to find a special burial shade of the intestine from the protobonelli, which is probably used as a food storage. Like a hamster that puts grass and grains in the hill bags, the protobonelly sags part of its catch on hungry times in a special intestine.

Then, when there is nothing at all at the bottom, the worm finishes the stored food. It is difficult for deep -sea residents to predict when to be lucky to eat next time - you have to show "evolutionary ingenuity"! Boetius A. Found a typo?