“What if Father misplaces you like his axes?!” “There’s nothing to worry about, your father has a grip comparable to the chelae of birgus latro. This allows me to peruse texts while still bonding with your father, and look! His posterior is within arm’s reach!”
Meet the coconut crab (Birgus latro), which holds the title of the world’s largest terrestrial crab (and indeed the world’s largest terrestrial arthropod). Found on islands of the Pacific and Indian oceans, it can reach a length of up to 1 m (3 ft 3 in), and a weight of up to 4.1 kg (9.0 lb) (see an especially large individual here: http://bit.ly/1UXlLhF).
The world’s largest land-living crustaceans, coconut crabs (Birgus latro), can grow up to a meter long, but their real claim to fame is
their strength: They’ve been known to lift more than 30 kilograms and
earn their names by cracking into coconuts to eat. Exactly how strong a
pinch from a coconut crab’s claw is, though, was a mystery—until now.
Researchers captured 29 coconut crabs on Okinawa Island in Japan and had
them clamp down on steel force sensors. Pinching forces ranged from
29.4 to 1765.2 newtons among the collected crabs. (For reference, the
human bite is about 340 newtons at most.) Because the crabs’ pinching
forces were significantly correlated to their body weights, the
researchers calculated that a 4-kilogram coconut crab should be able to exert a shocking force of 3300 newtons with its claw…