Description
Although we package crabs extra carefully, they remain very fragile. Therefore, shipping is at your own risk.
Crabs (Brachyura) are a group of crustaceans belonging to the order of decapods (Decapoda). The scientific name "Brachyura" literally means "short tail" and refers to the fact that their abdomen is folded under the plastron, which means that, unlike other crustaceans, crabs do not have a visible tail. Crabs are also called short-tailed or short-tailed lobsters because of their reduced abdomen. The underside of a crab is actually its tail, and this is a key difference from all other crustaceans. Crabs are further characterized by a flattened body that is wider than it is long and surrounded by dorsal carapace, distinct eyes on stalks, and the front pair of legs modified into prehensile pincers. Other notable features include their sideways locomotion and the ability to burrow quickly. Most crabs live in the sea and can be found from the deep sea to the intertidal zone. A few species have left the sea and adapted to life in freshwater. Some species are found primarily on land, usually in moist forests. However, crabs depend on surface water for reproduction. Many non-marine species must migrate to the sea annually to lay eggs. Crab larvae are microscopic and live as plankton in the open sea; the adults almost always live on the seabed. There are approximately 8,600 described species, which occur worldwide. In Belgium and the Netherlands, 38 species are known, either native or found more sporadically. See the list of crabs in Belgium and the Netherlands.
Like all crustaceans, crabs have a segmented body and legs. The body structure of crabs is characteristic because the body is broad and flat and appears to lack an abdomen. Due to their unusual body shape, crabs are even measured differently compared to other animals; the length from head to tail is not used as the measure, but rather the width of the carapace. Most crabs are medium-sized, about 5 to 15 centimeters. Many species remain smaller, while others can grow quite large. In terms of carapace length, giant crabs often do not exceed the North Sea crab (40 centimeters), but their enormous, harvestman-like legs make the animals look formidable. The claws are often very powerful. The very largest crab is the Japanese giant or spider crab (Macrocheira kaempferi), which is found in the Pacific Ocean around Japan at depths of up to 300 meters. Crabs have a carapace width of approximately 35 centimeters, but due to their enormous legs, their wingspan can reach about four meters and a 'shoulder height' of one and a half meters. The smallest crabs belong to the pea crabs (Pinnotheridae); they grow to about one and a half centimeters in length. The nail crab (Thia scutellata, family Thiidae) is also a small species that reaches a maximum carapace length of 22 millimeters. Among crabs, males are on average slightly larger than females.
Crabs can have a wide variety of colors; there are species that are entirely white, but black species also occur. A number of species have bright colors, such as red, blue, and purple. An example is the South American species Grapsus grapsus, which has a blue body with a yellow upper side and bright red legs. Most crabs, however, are well camouflaged and have a color that makes them blend in with the background of their natural habitat. Many crabs are sand-colored or have round spots, making them difficult to see against the pebbly bottom on which they live.
