World’s Strongest Pinching Force

If you were to guess the animal with the strongest bite, you might say lions or great white sharks. However, probably no one would suggest a crustacean known as the coconut crab (Birgus latro). Charles Darwin called this animal “monstrous,” and people who live in the South Pacific can tell amazing stories about the strength of this crab. However, it’s not the jaws but the claws of the coconut crab that have the world’s strongest pinching force.

The coconut crab is the largest arthropod on Earth. It can weigh more than nine pounds (4.1 kg) and grow to a width of three feet (1 m) from the tip of one leg to the other. Its claws are so powerful that they can exert a greater pinching force compared to its size than any other animal except alligators. The coconut crab is nocturnal and can use its claws to climb trees and even hang in one position for hours. They also use their claws, known as chelae, to defend against predators.

Other animals can’t break open a coconut, but coconut crabs can do that with their powerful chelae, making that food available to them. Although they are called coconut crabs and live on islands in the Indian and Pacific oceans where coconut palms grow, coconuts are not their primary food. Instead, they eat various fruits, nuts, seeds, the pith of fallen palm trees, carrion, and any organic matter they find on the ground. If they find something that interests them, they will grab it and carry it away, earning them the name “robber crabs.”

Some of the most important animals on Earth are those that cleanup waste. They include birds that eat carrion, insects that use dung in various ways, and many other life forms. Coconut crabs use the world’s strongest pinching force to process organic debris, so it will not cover Earth’s surface. 

An area of the planet with trees that produce tough materials like coconuts would eventually become buried in debris without animals that clean up the mess. Coconut crabs are so efficient that they eat their own exoskeleton when they molt, leaving nothing to contaminate the environment. Coconut crabs are one example of the many animals that recycle organic material. 

— John N. Clayton © 2022

Reference: Encyclopedia Britannica, Wikipedia, and PLOS ONE