Researchers find this species of crab has a massive claw strength, useful for protection and eating.
Don’t mess with a full-grown coconut crab! That’s probably a good piece of advice, according to an article posted on latimes.com. New research is saying the crab, known as Birgus latro, can pinch with about 750 pounds of force, and can lift as much as 66 pounds with its pincers.
Researchers just posted the findings from a new study in which measurements were taken on 29 coconut crabs on Okinawa Island by the Okinawa Churashima Foundation in Japan. The crabs ranged in weight from less than a pound to as much as almost five pounds.
The team measured the force of their pincers at 7-400 pounds of force, equivalent to 29-1,765 Newtons, and suffered a few painful pinches while doing so. During the analysis, they found the crabs’ pinching strength correlated well with the mass of the crustaceans, and they were able to calculate the strength of what was the largest coconut crab on record.
That crab, weighing in at nine pounds, would have had a pinching strength of about 750 pounds of force, quite amazing when you consider the average human’s bite is about 265 pounds of force. Crabs of this size would be among the strongest in the world, trailing only alligators and other such large animals.
The researchers speculate the crabs developed the strong pinching strength as they lost the need to carry a shell over years of evolution. Scientists believe these crabs share a common ancestor, a hermit crab species that lived about five million years ago. That ancestor, as many crab species today, would have carried a protective shell on its back.
By losing the shells, the coconut crabs grew larger and developed a hard, calcified abdomen, according to the researchers, but the young coconut crabs continue to carry a protective shell while they are very small.
But the claws are not just for warding off prey, says the team. The strength of the pincers allows them access to many types of foods unavailable to some of their competitors, items like other hard-bodied animals, some fruits and carrion.
As their namesake suggests, they also use these massive claws to open their favorite snack, the coconut.
Findings from the research were published in the journal PLOS One.