Crabs belong to the class Higher crayfish, type Arthropods, the order Decapods crustaceans. You can meet these animals on our planet everywhere. Crabs have five pairs of limbs. The first of them has long been turned into quite powerful claws. The size of these animals depends on the species. Typically, the width of the arthropod shell varies from two to thirty centimeters.
Variety of species
On the European coasts, land crabs are the most common. They can be found on the surf with soft soil. There is also a swimming crab. In this animal, the last pair of limbs is small lobes. Crabs of this species are excellent swimmers. They get their food in water. The closest relative of these two species is Chinese crab. The spider, a giant crab, lives near the Japanese islands in the Pacific Ocean.
Largest arthropod
Japanese crab spider belongs to the family Majidae. The scientific name of the arthropod in Latin is Macrocheira kaempferi. His crab received in honor of Engelbert Kempfer - German naturalist and traveler. This crustacean was first described in 1836 by Konrad Jacob Temmink, a Dutch zoologist.
Japanese spider crab (see photo below) is the largest of all arthropods.
The largest individuals of this type of crab have a carapace length of up to forty-five centimeters. Moreover, they are owners of fairly long legs. It should be said that the span of the first pair can reach three meters. Such a crab is equipped with forty-centimeter claws. They serve as a powerful weapon for an arthropod. There are individuals whose maximum body length with legs reaches four meters.
The chest and head of the Japanese crab are covered with short and flat carapace, ending with a sharp rostrum. Arthropod protection is provided by numerous spines and tubercles. They are located at the top of the carapace. The weight of these giants is often twenty kilograms.
At the depths of the ocean there is a high pressure created by the thickness of the water. However, the shell of a giant crab is protected from being pressed by a layer of durable chitin.
The joints of the legs of the animal are arranged in a special way. They allow him to move only sideways. The surfaces of the cartilage in the joint are very smooth. This greatly reduces friction.
Japanese spider crab is
an arthropod with an orange body. His legs are decorated with white spots. The eyes of the crab are located on the front of the head. Two spikes stick out between them.
Nutrition and Reproduction
The Japanese crab spider does the same job on the ocean floor as the vulture bird on land. It feeds on the skeletons of dead animals, mollusks and plants.
It is believed that this arthropod can live up to a hundred years. Find individuals of this species at a depth of one hundred and fifty to eight hundred meters. With the onset of spring, crabs rise closer to the surface. At this time, they can be found at a depth of fifty meters. Why is this happening? It is at this depth that the crabs are engaged in a continuation of their kind. During this period, there is a ban on their fishing.
During spawning, one female can lay one and a half million eggs. However, only a small number of them can survive to reproductive age. Predatory inhabitants of the ocean prey on small crabs. Those individuals that are larger become human prey. The Japanese crab spider is capable of reproducing offspring from the age of ten.
Eating
Crab meat is recommended for diet. It contains a small amount of carbohydrates and harmful fats. In addition, crab meat has a pleasant taste and is easily digested.
This delicious product is perfect for those who want to get rid of extra pounds. Coarse fibers, which are found in large quantities in crab meat, help in this process. The product is rich in taurine, iodine, vitamins and many other elements beneficial to human health.
Giant Japanese crab is often caught for food purposes. Only young individuals who did not have time to give offspring are suitable for fishing. The meat of such crabs is considered very tender. It is a delicacy everywhere. Unfortunately, the capture of these arthropods affects the reduction of their population.
And now for the adults. Due to the fact that their food consists of mollusks, carrion and all that is at a great depth fell, the meat of such spider crab acquires a bitter taste. Therefore, it is not suitable for gastronomic purposes. If such a specimen falls into the network of fishermen, then it is sold to the terrarium or water park to the delight of visitors.
Record crab
More recently, a huge specimen of this species of arthropods has been caught. He was given the nickname Crab-Kong. The size of this instance across is three meters. The distance between the claws exceeds 240 cm. But this crab will still grow. When he becomes an adult, he can easily ride a car.
Sea crab spider caught in fishing nets southwest of Tokyo, in the Suruga Bay area. Due to the fact that the gastronomic qualities of the meat of this animal are very highly valued, initially the fishermen planned to make soup from it. However, the crab was lucky. Fishermen contacted Robin James, a biologist who recently visited their village.
Currently, Crab Kong is housed in the Weymouth Sea Life Park, located in the English city of Weismouth. This fifteen-kilogram monster is the largest crab ever held in captivity.
Crab Kong, which is a true miracle of the deep sea, will not be long in Weismouth. After some time, it is planned to move it to Munich and place it in the Sea Life center.
Despite the fact that this specimen is considered the largest of those held in captivity, it is believed that the Japanese spider crab can reach such a size when the distance between its claws exceeds three and a half meters.
Interesting Facts
A young spider crab can grow only if it discards its outer hard shell. Under it is a soft inner, which the arthropod must have time to inflate before hardening.
In the event that the crab accidentally remains without a leg, a new one will certainly grow. Sometimes spider crabs ashore a sea wave. If the animal is entangled in the dam between the stones, then it will not be able to survive.