Hermit crabs are considered to be a family of decapod crustaceans. The average size of the individual is 9-10 cm, the largest representatives reach 17 cm in length.
There are more than 450 species of such cancers.
The body of hermit crabs is mostly soft,They do not have a strong shell, so most species protect their abdomen with the help of empty mollusk shells. With them, they hunt, they also hide in case of danger. Three pairs of limbs, including claws, usually protrude from the shell. The left claw hunters the cancer, and the right protects the entrance to the sink. In the process of evolution, the hermit's pair of paws was greatly shortened. It is they who now hold the shell while traveling.
Hermit crabs are found in the waters of the Baltic,Northern, Mediterranean seas, the islands of the Caribbean Sea, the coasts of Europe. As a rule, they choose shallow water and only some species, prefer a depth of 70-80 meters.
Hermit crabs are predators. They eat mollusks, worms, and other crustaceans. In addition, they are scavengers. By eating up the remains that decay near the shores of animals, the crayfish thus contribute to maintaining cleanliness in their habitat.
Shell of hermit crabs
As a shelter, hermit crabs choose themselvesShells about 25 species of shellfish. Without them, they are very vulnerable and easily become prey. The main criterion of choice is the ratio of the inner volume to the weight of the shell.
Since the hermit crab grows constantly, itRegularly in search of a new shell. Usually immediately after molting, he begins to look for a more spacious house. If there are a lot of shells in the area, then the replacement process takes place quickly and without problems. But if there are no shells, then the hermit crab looks at other similar cancers. If someone finds someone whose shell is clearly not the size, then with special tapping, he offers his fellow exchange. In case of consent, the neighbor gets out of the sink. However, if something does not suit him, then the hermit crab covers the entrance with a claw. Very often between cancers are real battles for a cozy living space.
Symbiosis of hermit crabs and anemones
Very often, hermit crabs settle on the sinkActinium, which protect them from enemies. Actinia in turn very quickly moves with them in search of prey. Actinia have poisonous tentacles, which paralyze the victim. Some crayfish prefer to plant actinia directly on the claw, which they block the entrance to the shell in case of danger. If you need to change the shell, then the hermit crab gently pincers its neighbor to its new home. Very often, hermit crabs that do not find a shell, settle the actinia directly on their body.