The crabs

Crabs are semiaquatic crustaceans that lives all over the world, they are arthropods and have an exoskeleton that protect them, they have ten legs, wich two of them are pincers, that are used for feeding and defending themself. 

There are over 4000 crab species, some of them lives in land but puts their eggs in the water.

Most crabs are omnivorous, they eat fishes, worms, molluscs and other crustaceans, they don't usually hunt their food but they wait to the tide to bring them dead animals. 

Coconut crab

Other crabs, like the Coconut Crab, climb the coconut palm to eat it's fruit, is the heaviest terrestrial crustacean in the world

 

 

Japanese Spider Crab

There are crabs that lives in fresh water and others in the sea, even in deep water, like the Japanese spider crab, that lives at depths between 50 and 600 meters. Their legs can grow to 3 meters long and can weigh to 19 kilograms.

 

 

And finally a curiosity. Why do crabs walk horizontally?

 Most crabs have a wide and short shell, and with a small abdomen, this lead to the evolution to make their legs grow to each side, so this method of walking is more effective to them to walk.