Crabs are decapod crustaceans of the infraorder Brachyura. source
Crabs are decapod crustaceans of the infraorder Brachyura.
Crabs live in all the world's oceans, in fresh water, and on land, are generally covered with a thick exoskeleton and have a single pair of claws. source
Crabs live in all the world's oceans, in fresh water, and on land, are generally covered with a thick exoskeleton and have a single pair of claws.
Many other animals with similar names – such as hermit crabs, king crabs, porcelain crabs, horseshoe crabs, and crab lice – are not true crabs. source
Many other animals with similar names – such as hermit crabs, king crabs, porcelain crabs, horseshoe crabs, and crab lice – are not true crabs.
Crabs are generally covered with a thick exoskeleton, composed primarily of calcium carbonate, source
Crabs are generally covered with a thick exoskeleton, composed primarily of calcium carbonate,
Crabs are found in all of the world's oceans, while many crabs live in fresh water and on land, particularly in tropical regions. source
Crabs are found in all of the world's oceans, while many crabs live in fresh water and on land, particularly in tropical regions.
Crabs vary in size from the pea crab, a few millimetres wide, to the Japanese spider crab, with a leg span of up to 4 metres (13 ft). source
Crabs vary in size from the pea crab, a few millimetres wide, to the Japanese spider crab, with a leg span of up to 4 metres (13 ft).
Crabs often show marked sexual dimorphism. Males often have larger claws, source
Crabs often show marked sexual dimorphism. Males often have larger claws,
Males Crabs have one claw which is greatly enlarged and which is used for communication, particularly for attracting a mate. source
Males Crabs have one claw which is greatly enlarged and which is used for communication, particularly for attracting a mate.
Another conspicuous difference is the form of the pleon (abdomen); in most male crabs. source
Another conspicuous difference is the form of the pleon (abdomen); in most male crabs.
Female crabs brood fertilised eggs on their pleopods. source
Female crabs brood fertilised eggs on their pleopods.
When development is complete, the female releases the newly hatched larvae into the water. source
When development is complete, the female releases the newly hatched larvae into the water.
Crabs typically walk sideways,(a behaviour which gives us the word crabwise). source
Crabs typically walk sideways,(a behaviour which gives us the word crabwise).
Crabs are mostly active animals with complex behaviour patterns. source
Crabs are mostly active animals with complex behaviour patterns.
Crabs are prepared and eaten as a dish in several different ways all over the world. source
Crabs are prepared and eaten as a dish in several different ways all over the world.
Crabs are often boiled alive. In 2005, Norwegian scientists concluded that crustaceans could not feel pain. source
Crabs are often boiled alive. In 2005, Norwegian scientists concluded that crustaceans could not feel pain.
The pincers of a crab, called chelae, are located on the front legs and are used for fighting, display and feeding. source
The pincers of a crab, called chelae, are located on the front legs and are used for fighting, display and feeding.