At the mention of clams, everything seems to be firstall remember the usual snails, and someone - gastronomic delicacies. Meanwhile, this is a separate type of animal, including a very large number of species that are completely different from each other, including sea scallops. What is it, or rather who, let's look in more detail.
Bivalve mollusks: class description
The second name of the class is the Lamellar.Bivalve mollusks on Earth are quite a lot, about 20 thousand species. They are well adapted to fresh and salt water. Compared with other mollusks, representatives of this class are sedentary bottom dwellers of reservoirs. They have a flattened body, closed in the sink, consisting of two wings. Most of them have very well-developed gills (ctenidia), having a lamellar shape (hence the name of the class), they serve not only the respiratory organs, but also original filters. Mostly bivalve mollusks are inactive inhabitants of the bottom. They are buried in silt, fleeing predators, clinging to rocks and other surfaces. Some are capable of short-term active movement, such as sea scallops. What is it, and more precisely who, we learn further.
The shells of bivalve mollusks, like the rest, are formed from calcium carbonate (CaCO3). In shape, they are two flaps, the same in size, which are interconnected by means of a protein ligament (ligament).
Sea scallops: what is it?
This is an extensive group of mollusks included inseparate family with the same name. They belong to the class plate. The habitat of its representatives is large enough. They are practically in all oceans and seas, absolutely at different depths. The waters of the subtropical and temperate zones are particularly rich in species. In Russia, these mollusks are found mainly in the Sea of Japan, as well as in the Bering Sea, the Sea of Okhotsk, and the Chukchi Sea.
Scallop: description
Как выглядят морские гребешки (фото можно увидеть in the article), they probably know everything. After all, not only are they very popular in cooking, their shells are a very common souvenir brought from sea trips. A characteristic feature of their external structure is a sink with flaps, slightly different in size and having “ears”. This is a special area behind and in front of the summit. The upper flap is flatter compared to the bottom. The surface of the shell, as a rule, is decorated with a radial or concentric convex pattern (ribs). Very often they have different types of thorns or scales, which gives even more decorative. The color of the shell may be different, depending on the habitat and which species the mollusk belongs to. Scallop by type of food - filter maker. A small mollusk (4 cm in diameter) can filter about 3 liters of water for one hour.
How do scallops move?
Representatives of the family of scallops - oneof the few bivalve mollusks that are capable of active swimming. They do it in two ways. In the first case, the mollusk moves forward in the abdominal region, while periodically slamming the shell flaps. This is explained as follows. Water accumulates in the mantle cavity, which all mollusks have, and its scallops have it. What it is, can be understood from the name. A special cavity, which is limited from the outside by the mantle (body fold), and inside by the body of the mollusk. Water can not go through the abdominal edge. It is ejected from the front and back of the dorsal edge. As a consequence, there is a jet thrust, which pushes the mollusk forward. Part of the water flows to the abdominal edge. As a result of this interaction of multidirectional forces, scallops move along the bottom with abrupt movements (forward and upward).
The second travel option is used.shellfish during the danger or sudden action of any stimulus. In this case, the mantle edge hanging from the sink quickly retracts inward, and water flows freely through the ventral edge. Scallop makes a sharp and long jump forward (up to half a meter). In nature, these mollusks have many natural enemies, for example, the starfish. This method of movement very often saves from predators and is defensive in nature.
Types of scallops
This family of mollusks is quite numerous, so we will focus on the most famous, commercial species of our country.
- Icelandic ScallopA fairly large view, the shells reach a size of 8-10 cm, and the maximum recorded weight is 600 g, but more often it does not exceed 150 g. It feeds on planktonic algae, which it filters out from the water column. Habitat - the waters of the Arctic and North Atlantic. Silty bottom does not like, prefers sandy, which settles or form colonies on stones.
- Scallop seaside. The size of the sink - up to 20 cm in diameter. Has white color and radially located edges. Habitat - sea waters off the coast of Sakhalin and Kamchatka.
- Black Sea scallop.The only species that lives in the waters of the Black Sea. It is small in size, the sink in diameter reaches 5 cm and has a bright color (yellow, pink, orange). The depth at which it occurs is 50-60.
Nutritional value of scallops
Морские моллюски, названия которых всем знакомы (scallops, mussels, oysters, etc.) are eaten from ancient times. It is known that they were actively caught and even bred in the Roman Empire. The usefulness of this product is undeniable for many reasons. Firstly, the scallop meat is 38% protein, which is a good alternative to ordinary pork or beef. In addition, it is low-calorie, (100 g only 88 kcal), so it, and indeed all marine mollusks (see the names above) is often recommended for people suffering from obesity or sticking to a diet. Secondly, the meat of scallops contains quite a lot of various macro- and microelements, including sulfur, molybdenum, zinc, nickel, and also vitamins, for example, PP. Everything is overshadowed only by the rather high price of this product. It is caused, first of all, by the difficulty of getting, and in fact, only a small part of the mollusk itself - the guard muscle (about 30% of the total mass) goes for food.
