A new study has found that the clumsy coconut crab is a species with more grip than any other animal.
According to new research published in the journal PLOS ONE, in fact, this crustacean’s claw is harder than most animals can bite – with the exception of crocodiles.
Shin-ichiro Oka – senior researcher at the Zoological Laboratory at Churashima Research Center in Japan – and his colleagues said: During this study, data was collected for analysis. This was a big challenge, as the large chunks of the crabs squeezed the researchers on several occasions.
However, Oka and his colleagues persisted and captured 29 coconut crabs in northern Okinawa to weigh and measure them. The coconut crab (Birgus lastro) is the largest land crustacean. It is related to the spiritual snail – they share a common ancestor over 2 million years ago. However, unlike the spirits snail, the coconut crab does not need to borrow a shell to protect it, its body is calcified and hard on the outside.
Coconut crabs are found along islands in the Indian and Pacific Oceans. This animal can weigh up to around 4 kg and can use its impressive claws to crack open the coconut.
Of all animals, ten-legged crustaceans, including crabs, lobsters, and shrimp, can produce the greatest force in terms of body weight with their claws. However, no one has ever tested the strength of a large weight coconut crab.
These giant coconut crabs are even able to climb trees and other vertical surfaces with their powerful legs. And their huge claws can crush seeds, fruits, and even the spongy kernels of fallen trees to eat them.
Researchers used a stainless steel sensor to test the grip level of 29 captured crabs. The results showed that the maximum grip strength ranged from 29.4 N to 1765.2 N.
In comparison, a 2010 study published in the Proceedings of the Royal Society B indicates that a single human bite can produce a force of up to 1300 N in molars.
Feats of strength
Of course, humans are much bigger than coconut crabs. It is the size of the body that determines the strength of this crab. Oka and his colleagues found that the bigger the crab, the stronger the catch. If the largest coconut crab weighs around 4 kg, scientists calculate that it can exert a clamping force as strong as 3300 N – greater than any other crustacean.
The researchers concluded that, based on body weight, this potency exceeds the potency that any animal can create, including alligators. Coconut crabs are unique and very aggressive species, often at war with other coconut crabs and with potential predators and competitors. Because they aren’t limited by shell size like their soul-coveting cousin, coconut crabs are able to freely develop exceptionally large bodies and claws.
