Shellfish

Shellfish, mollusks, the type of invertebrate animals, which includes snails, slugs, oysters, octopus, etc. There are more than 70,000 modern species and a large number of minerals. All shellfish, in principle, bilaterally symmetrical unsegmented body. Most have a sink in adulthood, and the rest - in the embryonic. The wall in the typical case it consists of three layers: a thin outer, konhiolinovogo (periostracum), which is a sink in the main owes its color, medium, prismatic (ostracum), consisting of calcium carbonate crystals, and internal (gipostrakuma) pearl. These layers are deposited skinfold - mantle. Although outwardly the representatives of different groups of mollusks vary greatly, they all share a number of characteristic structures, in particular foot, which the snail uses to crawl, perlovitsa - for burrowing into the bottom, and squid - for catching prey. Clams live in the seas, fresh water and on land. Depending on the symmetries and features of foot, mantle, nervous system and their shells are divided into five classes.Bokonervnye. The name of the class comes from the Greek. amphi - on both sides, and the neuron - a nerve. This marine forms, living mostly on the bottom of the shallow coastal waters. There are about 630 species. A typical representative - the coat. The body is bilaterally symmetrical bokonervnyh, sometimes vermiform, usually with inconspicuous head. Their shell is usually composed of eight transverse calcareous plates that cover the back. They feed on algae and shellfish, these hydroids.
 Gastropods. The name of the class comes from the Greek. gastr - belly, and pous - foot.These mollusks are different asymmetrical body, usually enclosed in a spiral shell, clearly visible head, and a broad flat foot. Well-known representatives of the gastropods, which include about 49,000 species - snails and slugs. In the past, as in some other form, shell rudimentary or absent, sometimes conical, not twisted into a spiral.

Starfish

    These echinoderms are generally flattened body, slowly turning into radial "arms" (5-40), which are called rays. The shape and structural features of the rays are very diverse: from the broad and short, giving the animal a pentagonal shape to long and thin, resembling tentacles. In contrast to the lily, the mouth and ambulacral grooves stars located on the bottom, facing the substrate surface of the body.

    In cases where the stars have the anus, it is like madreporite ambulacral system, is located on the right (dorsal) surface of the body.

     All Stars - mobile organisms moving along the substrate with the ambulacral feet, located in the ambulacral furrows. Like the lily, the stars are not expressed in the anterior-posterior axis and not a "head end". Stars - perfect radial animals.

    Very diverse skeletal plates and spines of stars, sometimes transforming into a special superficial organs - peditsillyarii. Under the microscope you can see that the pedicellariae is a group of several elongated "pits" that work like scissors or pliers. These tweezers stars can clean the surface of the body from a variety of fouling organisms, always willing to settle for such convenient "owners".

     Most of the stars - predators and corpse-eaters are known, and filter-feeders stars. Not rare, and cannibalism. When you capture a major victim of the stomach is able to turn out the stars of the mouth opening outwards and cover the prey.

     The larvae are called stars, and bipinnaria brachiolaria, but there is a star and direct the development, capable of nurturing their own young and care for their offspring. The larvae are able to eat during their development in the plankton, called planktotrophic, not feeding planktonic larvae are called lecithotrophic larvae.

     Who knows about 1500 species of sea stars, most of which are inhabitants of tropical seas.

     In the waters of the Southern Primorye, according to our data, 25 species inhabit the stars. Tell you about the most typical and frequent representatives

Seals

In one of his essays-known enthusiast of nature and a gifted writer and animal painter Gerald Durrell expressed this wish: "If I was not a man, I would like to be a sea lion". Males, which you see in the movies or pictures, really have to own graceful movements, the majestic, but not a fierce kind of large males, kind and gentle eyes of young females, playful games of children. Closer acquaintance with their lives a few dispels this illusion.
  All through the autumn, winter and early spring the northern fur seals is carried out in the open sea, where the catch of cephalopods and fish. They swim and dive admirably and in search of food in the ocean doing a long journey, following temperate and cold regions. With the coming of spring, the instinct of reproduction leads to the shores of the seal islands, where they saw a life. On the small island of seals that are in the Sea of ​​Okhotsk, not far from Sakhalin Island, in early May, adult males emerge first, bill hooks. They are chosen on the beach and take it to the sites at a distance of 2-5 meters from each other.
 Each seal fiercely protects the occupied territory from neighbors and newcomers belated males. Between the chopper often have ferocious fights, sometimes resulting in serious injury. Here is a competition not only in strength but also endurance. The fact is that by taking part of the beach, chopper can not leave it until the end of the breeding season. Otherwise, it will take place immediately one of the competitors.
It takes a month, and the island of countless herds of females swim. Males do not like to be disturbed during the breeding season, in addition, they are very picky in choosing the rookeries. Therefore, in the places that they seem appropriate, gather hundreds, sometimes thousands of animals.
 Huge and overweight, overfed males during the winter waiting for the arrival of females on the beach, and everyone tries to get them in his harem.