Crabs are very appreciated in cooking, dishes of them make up an important part of dishes in the kitchens of many peoples of the world. Their production accounts for 20% of all seafood in the world. There are many types of these arthropods, and it is important to know which of them are edible.
Characteristic and description
Crab is also called shorttailed cancer. Its biological characteristics are as follows:
Of the 10 paired limbs in crab 2, the front are powerful claws. The animal is aggressive due to the need for self-defense and the search for food, therefore it regularly participates in fights in which it can lose one of its claws. In its place, as a rule, a new one grows. Because of this, crabs with an asymmetric body are often found.
4 more pairs of legs are called walking. It is they that allow the crustacean to move at different speeds, mostly sideways. For example, a swimming crab in water can make 780 strokes of its legs per minute, while another species, grassy, develops a speed of 1 m / s on land.
The structure of the crab
The arthropod carcass has the following composition:
The abdomen is short, symmetrical and bends longitudinally under the cephalothorax. Its shape is round, square, triangular in some species.
The outer skeleton consists of a chitinous substance and is called the carapace. It provides the internal organs of the crab with protection from external mechanical influences and other environmental influences.
The hard cover is formed by several layers: inside is soft organic-type chitin, outside is calcareous, which gives it strength. The substance contains pigments that color the crab a certain color.
Due to the strength and rigidity, the shell significantly limits the animal in growth. Therefore, the crab sheds it in certain periods, until it reaches its final size. During molting, a new integumentary layer grows under the carapace, and the old exoskeleton bursts and falls off.
Crabs are dioecious animals, the differences between females and males are significant. Males are much larger than females. Sexual maturity occurs at the age of:
Arthropods reproduce by laying eggs. In males, the abdominal legs are also genital organs with the functions of internal fertilization. Females hatch eggs on their limbs. One such clutch usually contains about 40,000 eggs.
The development of a small crab takes place in several stages:
Crase propagation occurs in a certain season. In each species it correlates with some natural phenomena. It can be rainy seasons or intensive tides at one or another of the year.
So, the place of residence of the red crabs of the island of Christmas is a land away from the coastline. But during the breeding period, they massively migrate to the surf line in order to launch eggs. This movement is considered one of the most spectacular natural phenomena.
Hills of crabs
The usual habitat of crabs oceans and sea, less often freshwater reservoirs of large sizes. Some species are adapted to live on land. The basis of the food is fish, mollusks, worms, underwater vegetation, larvae, crustacean. The remains of different animals are also used.
The crab uses forelimbs with claws to tear and grind food.
The arthropod has many natural enemies. Basically, these are organisms that are adjacent in the reservoir, for example, squid and cuttlefish. It can also be land animals, birds and, of course, humans. Therefore, crabs adapt to external influences.
Defense mechanisms include:
Thanks to this, a crab can be indistinguishable from a stone, a group of corals or a ball of algae.
Differences between crabs and crayfish
Since both of these animals are crustaceans, they have a lot in common. Of the same characteristics can be called:
There are more external differences. The crayfish has a long body, close to cylindrical, with a lamellar coating, ending in a tail. The crab is tailless, the shape of the carcass is different, and the chitin is solid.
The mode of travel is also different. Cancer is characterized by walking backwards. He moves forward very slowly due to massive claws that make it difficult to move. The crab mostly walks sideways, and rather quickly.
About 7,000 varieties of crabs are known. They are distinguished by the area of residence, the size of individuals, the shape and color of the shell. For the fishing industry, only some of them are of interest, they are large, with juicy meat, and do not have protective mechanisms of a toxic type.
Japanese spider crab
This species is the largest member of the arthropod order. The width of the spider crab from one claw to another reaches 3 m. An adult weighs about 20 kg. The name was given by the shape of the legs: they are thin, very long and reminiscent of spiders.
Thanks to its delicate taste and juiciness, spider crab meat is classified as a delicacy.
The animal lives mainly in the waters of the north-eastern seas-Bering, Okhotsk and Japanese. This species is especially valuable in Eurasia among commercial rocks.
The name Krab was thanks to blue spots on the sides of the shell. The lower surface of the abdomen is white. Dimensions and weight vary depending on the gender: the male grows to 22 cm and 4.5 kg, the female 16 cm and 1.5 kg.
The dimensions of this species are very small, the width of the shell reaches 28 mm. On the surface there are many bristles of a yellowish tint. Hairy crab off the coast of Sakhalin.
Fineword meat due to the fibrous structure has a specific taste. But the liver of this crab is of particular value. She is delicate, tasty, slightly acidic. It is believed that the liver belongs to aphrodisiacs along with oysters.
There are individuals of hairy crab, which have no liver at all.
The species lives in the waters of the Black Sea, it is among the most common in this region. The sizes of such crabs are small, usually they grow up to 4.5-4.8 cm. The limbs and the top of the abdomen are covered with a characteristic pattern, due to which the species was given this name.
The marble crab has the ability to be out of the water for a long time and spends a lot of time in land conditions.
green grass crab
The size of specimens of this breed does not exceed 6-8 cm. Habitat mainly the Black Sea coast. Coloration helps the grass crab to camouflage itself in algae or overgrown rocks.
It is believed that the grass crab is the fastest species of arthropods. In case of danger, it develops a speed of 1 m / s.
Chinese mitten crab
The species owes its name to the dense dark hairs on the forelimbs. The size of the shell is not more than 7 cm in width, its color is brown or with an olive tint.
Chinese mitten crab more often than other species becomes a carrier of crayfish plague, a disease dangerous to humans.
Another name is “palm thief”. The uniqueness of the species is that for the first 5 years it lives exclusively in the sea, and then finally moves to land. From that moment on, the basis of his diet is fruit pulp, coconuts, small rodents and other terrestrial foods.
The species is large (reaches 40 cm in transverse abdomen), therefore it is popular as a delicacy.
The main habitat of the species is the Baltic, North and Mediterranean seas. This crab owes its name to a beautiful color in blue and turquoise tones over the entire chitinous surface.
Despite its small size and small amount of meat, this species is successfully harvested. In addition, it is very popular in cooking. The meat is soft and tender, has no fibrous structure. It is usually used as an accompaniment to main dishes.
Red mangrove crab
This breed belongs to decorative ones, it is practically not used in cooking. Mangrove crabs decorate aquariums. Their sizes do not exceed 4-5 cm in males and 3 cm in females.
In nature, the habitat is mangrove forests. Because of this, the species was named.
Maltese freshwater crab
The distribution area of the species is the southern regions of Europe: the Balkan Peninsula, the Apennines, Sicily and Malta. The crab is omnivorous, lives in lakes, rivers, streams mostly freshwater reservoirs. Therefore, its second common name is river crab. The width of the shell is 12 cm, weight 130 g.
Another name for the species is tree crab. Belongs to land, practically does not need water. The main habitat is the coast of the Caribbean islands, mostly sandy.
Hermit crab omnivorous scavenger. Its distinctive feature is a spiral shell. This form is not typical for other types of arthropods.
The habitat is the sea coast of the Pacific Ocean, sometimes the spiny crab can live in fresh water. The size of the abdomen is 14 cm wide, there are many spikes on the shell, for which the species received its name. It is also called the Pacific hermit crab.
The main food of the species is molluscs. Thanks to this, the meat acquires a sweetish taste and juiciness.
Madagascar freshwater crab
As the name suggests, these small arthropods live in the forests of Madagascar. The carapace on the abdomen is about 6-8 cm wide.
The crab has a special color: yellow claws and torso, walking limbs are rich pink.
Pebble clown crab
This species is not used in cooking due to its high toxicity: the poison in the meat is not destroyed even during heat treatment. The clown crab usually serves decorative purposes. Its bright orange carapace is covered in a variety of patterns.
The benefits and harms of crab meat
Due to its high palatability, the meat of most types of crab is very popular in many cuisines of the peoples of the world, especially in coastal regions. It is also good for the body.
Crab meat is low in calories, but rich in micro and macro elements, such as:
It also contains vitamins A, C, E, PP and almost the entire group B.
In 100 g. boiled crab meat contains:
The composition of the product is unique, it provides an improvement in the functioning of the heart muscle and visual organs. Crab meat is recommended for anemia and disorders of the cardiovascular system.
On sale, the product is found in canned, boiled and dried form, it is used in many dishes, especially dietary. Proper use of meat will provide:
But it is worth remembering that most crabs are scavengers that feed on the remains of animals. This makes them dangerous carriers of infections and parasitic organisms. Eating infected meat can lead to toxic poisoning, as a result, disorders of the nervous system, up to loss of vision and hearing.
To protect your health from harmful effects, you need to buy crab meat only where the quality control of the product is documented.
Also, the product can be dangerous for people with individual allergic intolerance to seafood.
How to cook and eat crabs
Such a popular product as crab meat is very important to be able to not only cook, but also serve on the table. This usually consists in heat treatment: the meat is steamed or boiled, adding olive oil and fragrant herbs. On average, cooking takes 30 minutes, but the time may vary depending on the size of the animal and its weight.
The most popular addition to crab meat is aioli sauce or melted butter. Sauces with richer flavors such as tartar and wasabi are often used. As a side dish, use spaghetti or cereals of any type.
Crab meat, like most seafood, pairs perfectly with white wine.
Self-cutting crab, fresh or boiled whole in shell, is done according to the following algorithm:
Now you can use the cooked product for your favorite dishes.
Like any other class of animals with great species diversity, arthropod crustaceans often surprise with something unusual. Many interesting things can be found in the life of crabs:
Crabs are popular not only in cooking. They are also called orderlies of nature. This is especially important in the tropics, where these crustaceans actively destroy organic matter, preventing its long-term decomposition in the heat. So they directly prevent the spread of infectious diseases.