Fun Facts About Crabs

• Crabs are decapods from the crustacean family. 

• Decapod means "ten-footed". Crabs have 10 legs, however, the first pair are its claws which are called chelae. 

• Crabs have a thick external skeleton called an exoskelet on. It is a shell made of calcium carbonate and provides protection for the soft tissue underneath.

• Crabs live in all the world's oceans, in fresh water, and on land. There are over 4500 species of crabs. 

• Other animals with similar names such as hermit crabs, king crabs, porcelain crabs, horseshoe crabs and crab lice, are not true crabs.

• Crabs usually have a distinct sideways walk. However, some crabs can walk forwards or backwards, and some are capable of swimming. 

• The collective name for the group of crabs is a cast.

• Crabs communicate with each other by drumming or waving their pincers. 

• Male crabs tend to often fight with each other over females or hiding holes.

• The Pea Crab is the smallest known species at just a few millimetres wide. The largest species is the Japanese Spider Crab, with a leg span of up to 4 m (13 ft). 

• Crabs are omnivores (meaning they eat both meat and plants), they feed mainly on algae, but also bacteria, other crustaceans, molluscs, worms, and fungi.

• Some crab species can naturally autotomise (shed) limbs such as their claws, which then regenerate after about a year. 

• Of all marine crustaceans caught be humans each year, crabs make up 20%. This adds up to a total of 1.5 million tonnes annually.

• The most consumed species of crab in the world is the Japanese Blue Crab.