Heavyweight Crustacean: Coconut Crabs Can Pinch Like Lions, Lift More Than 66 Pounds
Scientists reported on Wednesday that Birgus latro, the largest land-dwelling crab in the world, are so strong that it can pinch at about 750 pounds of force (3,300 newtons) and even lift 66 pounds.
A team of researchers from Okinawa Churashima Foundation in Japan came up with these shocking numbers after measuring the pinching strength of 29 coconut crabs located on Okinawa Island. Their results were published in the journal PLOS One.
The researchers noted that the coconut crabs observed on the island varied in size and intensity of pinch, from coconut crabs weighing only a pound to the largest the team has ever recorded at 9 pounds. The variation in size led the researchers to conclude that the pinching strength is correlated with the crab's size. The giant 9-pound coconut crab they found can pinch up to 750 pounds (3,300 newtons) of force.
For an animal, 750 pounds of force is extremely strong. The Los Angeles Times notes that a human's bite only measures 265 pounds of force on average while an Olympic boxer's punch could produce 770 pounds of force.
Science notes that the coconut crab's strong weapon, their claws, allows them to access other normal sources of food such as coconuts that most of their cousins could not reach. This adds to the list of evidence that this species has "diverged from humble hermit crabs some 4 million years ago."
"The mighty claw is a terrestrial adaptation that is not only a weapon, which can be used to prevent predator attack and inhibit competitors, but is also a tool to hunt other terrestrial organisms with rigid exteriors, aiding in these organisms to be omnivores," the study wrote.