The coconut crab (Birgus latro) is a type of land hermit crab. The claws of coconut crabs have the strongest pinching force of any crustacean, according to research. What’s more, their maximum crushing force is stronger than the bite force of all land animals, except the alligator. Coconut crabs are remarkably strong, lifting up to 28 kilograms (62lb) – the weight of a small child. They use their claws to fight and defend themselves, as well as to crack open coconut shells. At up to one-metre (3 ft) across, coconut crabs are also the largest of all land-based arthropods – the group that includes insects, spiders and crustaceans. They live on small islands in the tropical Indian and Pacific oceans. Researchers in Japan measured the squeezing force of 29 wild coconut crabs living on Okinawa Island using a sensor. They calculated that a large crab could be expected to exert a squeezing force of more than 3000 newtons, which exceeds other crustaceans, such as lobsters. “The mighty claws of these crabs are useful weapons to deter predators and competitors,” say scientists from the Okinawa Churashima Foundation. “In summary, coconut crabs have the ability to exert the greatest force among almost all terrestrial animals.” Coconut crabs are well adapted to life on land. Unlike most crabs, they only return to the sea to lay their eggs. They can also climb trees and cut coconuts down. Despite their size and strength, little is known about coconut crabs and whether or not they are a threatened species.

hermit crab: n. 寄生蟹

pinching force/ crushing force/ squeezing force: n. 夹力

crustacean: n. 甲壳纲动物(如蟹、龙虾)

arthropods: n. 节肢动物

exert: v. 运用，发挥；施以影响

mighty: adj.  有力的