More than 70 thousand various crustacean creatures live on our planet. They are found in almost all reservoirs of the world: in rivers, lakes, seas and, of course, oceans. With all the variety of crustaceans, even today not all of their species are well studied by zoologists. One of the most prominent representatives of this subtype of animals is the large marine lobster, hermit and mantis.
Who are crustaceans?
So it is customary to call a huge group (subtype) of arthropod animals. These include crabs, shrimps, crayfish, sea crayfish (mantis, hermits, lobsters), lobsters , etc., which are well known to us. Currently, scientists have described about 73 thousand species of these creatures. Representatives of this group of animals mastered almost all types of reservoirs on our planet.
The vast majority of crustaceans are actively moving creatures, but in nature you can also find motionless forms, for example, sea ducks or sea ​​acorns. It is worth noting that not all crustaceans are marine animals, some of them, for example, crabs and wood lice, prefer to live on land.
Lifestyle
Crustacean animals, including lobster, and mantis, and hermit crab, are both large and small within their family and species. Many of these animals can be perfectly masked, radically changing their color to the color of the surrounding soil, for example, blue lobster. As already mentioned above, while some crayfish run, swim and climb everywhere, others prefer a passive lifestyle, attaching themselves to various underwater objects.
Many crustacean creatures defend themselves from enemies with the help of calcareous shells, but not all have such an opportunity. For example, large marine lobster cancer, as well as shrimp and crab, do not have shells at all. Their body is covered with a reliable carapace consisting of durable chitinous plates. Familiar to all crayfish have such shells.
Breeding
Sea crustaceans breed by laying eggs. In all large crayfish, they look like 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 can hatch. The vast majority of them go to feed fish and other marine animals.
So, let's take a closer look at several prominent representatives of the subtype of marine crustaceans : mantis crab, hermit crab, and lobster (lobster).
Mantis Cancer
These animals live at 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 primary colors and their shades, then mantis shrimps see a spectrum consisting of 12 colors. Scientists who studied these animals are sure that they see infrared and ultraviolet colors, as well as different types of polarization of the light flux.
Mantis lifestyle and hunting
Marine mantis shrimp is a rather aggressive creature leading a solitary lifestyle. He spends most of his time in crevices or in soil burrows. Praying mantis shrimps leave their shelters only if they seek food or change their habitat. These creatures catch their prey with the help of sharp and jagged joints on grasping legs: during an attack, a sea mantis cancer makes several quick and powerful kicks on the victim, killing it. Animals feed on small crustaceans as well as gastropods. They do not disdain carrion.
Cancer hermit
These creatures have an unusual appearance. In many ways, it depends on their habitat. Hermit crabs are chained in a spiral-twisted shell. 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 cork: with it, the marine hermit crab plugs the entrance to its own shell.
Hermit lifestyle
The name of this type of sea crayfish speaks for itself: they lead a solitary lifestyle. Most hermits use shells left over from gastropod mollusks as dwellings and shelters . These creatures inhabit the tidal zones and at shallow sea depths. Some hermit crabs can leave the water element for a long time, returning to the sea only during their breeding season. Hermit crabs are typical corpse eaters.
Lobster (Lobster)
It is a large marine cancer of the invertebrate family. At first glance, this creation may remind everyone of the known crayfish, but there is still a difference between them. All representatives of this family are distinguished by huge clawed limbs. Otherwise, they are very similar to ordinary crayfish.
How to recognize lobster?
To distinguish a real lobster from one or another large cancer, you need to pay attention to its claws and legs. The fact is that true lobsters have quite massive claws located on the first pair of legs. These animals also have claws on the second and third pairs of legs, only several times smaller than those on the first. In total, these creatures have five pairs of limbs.
External description of lobsters
Lobster is a marine cancer that inhabits the vast majority of the water bodies of our planet. Its powerful claws are an indispensable tool for obtaining food and protecting against all kinds of sea enemies. On the head of the lobster are three pairs of jaws. The most powerful are the so-called mandibles, with which crustaceans chop food. The remaining jaws filter it. Incidentally, shell lobes easily break open with their large claws.
These creatures consume everything that is organic in food, that is, they eat everything that falls into their claws. To do this, they wander for hours on the bottom of the sea. As with all crayfish, the lobster's favorite food is the semi-decayed remains of marine animals. They do not disdain small crustaceans, snails, mollusks and other invertebrates.
The eyes of the largest marine cancer in the world are made up of many small and separate eyes called facets. Surprisingly, one lobster eye can consist of 3,000 facets! Not only in deep-sea crayfish. The bristles located on the head replace the sensory organs. With the help of them, lobsters sense, 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 exceptionally cool and medium-salted waters, whose temperature is not higher 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 from the Atlantic.
This marine cancer has a pronounced sexual dimorphism, i.e. males are always much larger than females. The abdominal department in these animals is developed quite well: all appendages and segments are distinguishable without any difficulty. The chitinous shell of lobsters sheds from time to time.
The musculature of the body in these animals consists of specialized and well-developed muscles. The life expectancy of male lobsters ranges from 25 to 32 years, and female lobsters - up 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.
Lobster behavior in danger
Omar is a marine cancer that can injure itself for its own safety. For example, when capturing the limbs by any enemy, lobsters drop them without hesitation, that is, they independently lose their own legs (sometimes up to six at a time). This allows them to escape from danger, hiding in shelter.
Lost limbs are regenerated over time, that is, restored. True, the process of their full restoration can take several years, but what to do - your own life is more expensive. And lobsters understand this very well.
Why does a lobster die?
First, lobsters, like other crustaceans, are links in the food chain. In other words, they feed many marine fish, baleen whales (as main food) and birds. It’s a sin to hide, lobsters and other crayfish, as well as shrimp, oysters, crabs - this is people's favorite delicacy food. It even got to the point that whole factories are currently being built, where crayfish are specially bred for further consumption.
Secondly, lobsters are quite sensitive to the chemical composition of water. A deadly threat to these animals is the constant pollution of water by various industrial wastes, slags and other garbage.
Cooking Lobsters
As already noted, in cooking, large sea crayfish is considered an exquisite delicacy. People eat his meat, which is famous for its tenderness. The food is meat from the shell, as well as from the legs and host of lobsters. In addition, people eat caviar and liver of these animals. In restaurants, soufflés, soups, salads, jellied dishes, croquettes, mousses, etc. are prepared from crustaceans.
The extermination of lobsters
The crustacean population is constantly declining. From the middle of the 19th century, the first attempts were made to breed lobsters in artificial reservoirs. At the beginning of the XXI century, this lesson gained full momentum. However, until now people cannot find a commercially viable method of cultivating sea crayfish.