Large sea cancer: photo and description. Marine hermit crab

On our planet there are more than 70 thousand all kinds of crustaceans. They are found practically in all water bodies of the world: in rivers, lakes, seas and, of course, oceans. With all the diversity of crustaceans, even today not all of their species are well studied by zoologists. One of the brightest representatives of this subtype of animals are the large sea lobster, a hermit crab and a mantis dog.

Who are crustaceans?

So it is customary to call a huge group (subtype) of arthropod animals. These include well-known crabs, shrimps, crayfish, sea crayfish (mantises, hermits, lobsters), lobsters, etc. At present, scientists describe about 73 thousand species of these creatures. Representatives of this group of animals have mastered almost all types of reservoirs on our planet.

The vast majority of crustaceans are actively moving creatures, but in nature one can also find fixed forms, for example, sea ducks or sea acorns. It should be noted that not all crustaceans are marine animals, some of them, for example, crabs and lice, prefer to live on land.

Lifestyle

Crustaceans, including lobster, and mantis, and hermit crab, are within their family and species, both large and small. Many of these animals can perfectly mask themselves, radically changing their coloration to the color of the surrounding soil, for example, a blue lobster. As already mentioned above, while some crayfish run, swim and climb everywhere, others prefer a passive way of life, attaching themselves to one or another underwater object.

Many crustaceans are protected from enemies by calcareous shells, but not all have this capability. For example, a large sea lobster, as well as shrimp and crabs do not have shells. Their body is covered with a reliable shell, consisting of strong chitinous plates. Such shells are also familiar to all river crayfish.

Reproduction

Marine crustaceans multiply, laying eggs. All large cancers are similar to fish eggs. For example, lobsters lay their eggs in incredibly large quantities - from 1.5 to 600 million pieces per period. Of course, not all eggs will be able to hatch crayfish. The overwhelming majority of them go to feed fish and other marine animals.

So, let's consider in detail several bright representatives of the subtype of marine crustaceans : mantis crayfish, hermit crab and lobster (lobster).

Praying mantis

These animals live in shallow depths in the subtropical and tropical seas. Their unique feature is the most complex eyes in the world. For example, if we can distinguish only three basic colors and their shades, then the mantis shrimp sees a spectrum consisting of 12 colors. Scientists who have studied these animals are sure that they see infrared and ultraviolet colors, as well as different types of polarization of the light flux.

Lifestyle and hunting mantises

Sea mantis cancer is a fairly aggressive creature, leading a solitary lifestyle. Most of the time he spends in crevices or in subterranean burrows. The mantis shrimp leave their refuge only in the event of a search for food or a change of habitat. Their prey is caught with the help of sharp and serrated segments on the grasping legs: during the attack, the sea mantis shrimp performs several quick and powerful kicks on the victim, killing her. The animals feed on both small crustaceans and gastropods. They do not disdain and carrion.

Cancer hermit

These creatures have an unusual appearance. In many ways, it depends on the place of their dwelling. Hermit crabs are encased in a spirally twisted armor. Outside, only three pairs of walking legs are visible. On the first pair are claws of different sizes. The largest claw plays the role of a cork: by her sea hermit crab, it plugs the entrance to its own shell.

The way of life of hermits

The name of this species of sea crayfish speaks for itself: they lead a solitary lifestyle. As a home and shelter, most hermits use shells left over from gastropods. These creatures dwell in tidal zones and in shallow sea depths. Some hermit crabs can leave the water for a long time, returning to the sea only during their breeding season. Hermits are typical corpses.

Lobster (lobster)

It is a large marine cancer of the family of invertebrates. At first glance, this creation can remind everyone of the famous river cancer, but there is still a difference between them. All representatives of this family are distinguished by huge clawed extremities. In the rest they are very similar to the usual crayfish.

How to recognize a lobster?

To distinguish this lobster from this or that large cancer, it is necessary to pay attention to its claws and legs. The fact is that the true lobsters have quite massive claws, located on the first pair of legs. On the second and third pair of legs, these animals also have claws, only a few times less than those on the first. In total, these creatures have five pairs of limbs.

Exterior description of lobsters

Omar is a marine cancer that inhabits the vast majority of the reservoirs of our planet. Its powerful claws are an indispensable tool for obtaining food and protecting against all sorts of sea enemies. On the head of the lobsters are three pairs of jaws. The most powerful are the so-called mandibles, by means of which the crustaceans chop the food. The remaining jaws are filtered. By the way, lobster shell lobes easily crack their big claws.

In food these creatures consume everything that has an organic nature, that is, they eat everything that comes to their claws. For this they wander for hours on the bottom of the sea. Like all crayfish, the lobster's favorite food is the half-rotten remains of marine animals. They also do not disdain small crustaceans, snails, mollusks and other invertebrates.

The eyes of the largest marine cancer in the world consist of many small and individual eyes, called facets. Surprisingly, one lobster eye can consist of 3000 facets! They are not found only in deep-sea crayfish. The bristles located on the head replace sensory organs. With the help of them, lobsters feel, smell and determine the chemical composition of water.

General description of lobsters

Lobsters, like many marine animals, breathe with gills. They are located under their shell. These creatures prefer extremely cool and mid-salty waters, the temperature of which is not more than 20 degrees Celsius. Lobsters can hardly be found in the seas washing the coast of our country, since their habitat is limited to the Scandinavian peninsula by the Atlantic.

This sea cancer has a well-expressed sexual dimorphism, that is, males are always much larger than females. The abdominal region in these animals is developed quite well: all appendages and segments are distinguishable without any difficulty. The chitinous shell of lobsters occasionally sheds.

The musculature of the body in these animals consists of specialized and well-developed muscles. The life span of male lobsters ranges from 25 to 32 years, and female lobsters to 55 years. According to the Guinness Book of Records, the largest marine lobster cancer was caught in Canada (Nova Scotia). Its weight was 20.15 kg.

Behavior of lobsters in danger

Omar is a marine cancer that can injure itself for its own safety. For example, when you capture a limb by an enemy, the lobsters discard them without hesitation, that is, they themselves lose their own legs (sometimes up to six at a time). This allows them to escape from danger, hiding in shelter.

The lost limbs are regenerated with time, that is, they are restored. True, the process of their full restoration can last several years, but what to do - your own life is more expensive. And lobsters understand this perfectly.

Why is the lobster dead?

First, lobsters, like other crustaceans, are links in the food chain. In other words, they go to feed many sea fishes, moustached whales (as the main food) and birds. What is a secret, lobsters and other crayfish, as well as shrimp, oysters, crabs - this is a favorite delicacies people eat. It even went so far that at the present time whole factories are being built where the crayfish are specially bred for further consumption in food.

Secondly, lobsters are quite sensitive to the chemical composition of water. A deadly threat to these animals is the constant pollution of water with various industrial wastes, slags and other debris.

Lobsters in Cooking

As already noted, in cooking, a large sea crab is considered an exquisite delicacy. People eat his meat, which is famous for its tenderness. Meat is used for food from under the shell, and also from the legs and host of lobsters. In addition, people eat caviar and liver of these animals. In restaurants from crustaceans, soufflé, soups, salads, luncheons, croquettes, mousses, etc., are prepared.

Extermination of lobsters

The crustacean population is constantly shrinking. From the middle of the XIX century, the first attempts were made to cultivate lobsters in artificial reservoirs. At the beginning of the XXI century, this occupation gained full momentum. However, until now people can not find a commercially profitable method of cultivation of sea crayfish.