Stay safe and never try to mess with coconut crabs, Birgus latro, as their pinch will be too hard to handle.

The crab with strong claws is counted as one of the strongest terrestrial animals, with a pinching power exceeded only by alligators' and some other species' bite power.

According to a new study, the largest terrestrial crab has the power to pinch with a force of 750 pounds. Compare this with the moderate bite power of humans exerting just 265 pounds of force, and a trained boxer's punch may be some 770 pounds of force.

Found in islands of the Pacific and Indian oceans, these crabs with powerful claws carry an upper hand in accessing foods their rivals may not get, including coconuts, of course.

The pinching force of the coconut crab varies in direct proportion to the body mass. The maximum force can be 3,300 newtons based on the animals' weight.

Study Conducted In Japan

The findings came from a study by Okinawa Churashima Foundation in Japan. During the study, the researchers measured the pinching prowess of 29 wild coconut crabs on Okinawa Island. The details of the study have been published in the journal PLOS One.

"We expected the force would be very strong. But the actual powers exceeded our expectation," study lead author Shin-ichiro Oka, a chief researcher at the Okinawa Churashima Foundation said.

In terms of size, coconut crabs can have weight up to 4 kilograms, length up to 40 centimeters and leg span almost a meter. The study adds that the terrestrial crustacean is so strong that it can lift 28 kilograms of weight and fight enemies with claws.

Since the bite varies with the weight of the animal, crabs with a range of weight were chosen. They ranged from less than one pound to 5 pounds with bites exerting 7 to 400 pounds of force (29 to 1,765 Newtons).

In terms of mass, decapods had been ahead with the greatest pinch power, but no hard details on the pinching force of coconut crabs.

Hard Evolution

According to scientists, the mighty claws of coconut crabs might have evolved after they ceased to have the need to carry a shell. Some 5 million years ago, this descendant from a hermit crab might have carried hard a snail shell on its back.

When stripped of shells, the crabs grew larger and acquired a calcified abdomen later on.

As for crocodiles, they have a super bite force of 16,460 newtons while lions, tigers, and hyenas snap jaws with a force of 4,450 newtons.

Unlike big cats, coconut crabs do not snap their claws, rather applying a crushing force when they pinch.

Photo: Drew Avery | Flickr