The ocean’s depths harbor fascinating creatures, and crabs, with their armored exoskeletons and unique forms, spark interest in their immense sizes. Many wonder about the largest among them, seeking to discover the record holders.
The Record-Breaking Catch
The largest crab ever recorded by leg span is the Japanese Spider Crab (Macrocheira kaempferi). This deep-sea inhabitant holds the record for the greatest leg span of any arthropod, reaching up to 13 feet (4 meters) from claw to claw. One widely documented specimen, nicknamed “Big Daddy,” measured 10 feet, 2.5 inches (3.11 meters) wide and had a leg that stretched 4 feet, 8.5 inches (1.43 meters).
These crabs typically weigh around 40 pounds (16-20 kg), though some can reach up to 42 pounds (19 kg). Japanese Spider Crabs are primarily found in the Pacific waters around Japan, inhabiting sandy or rocky bottoms.
The Species Behind the Record
The Japanese Spider Crab’s impressive size is attributed to its deep-sea habitat. It lives at depths between 160 to 1,970 feet (50 to 600 meters), where water temperatures remain consistently cool, around 50-55°F (10-13°C). This cold, stable environment allows for a slow metabolism and extended growth, contributing to their remarkable longevity, with some individuals estimated to live up to 100 years.
These crabs are omnivorous scavengers, consuming dead animals, algae, and mollusks from the seafloor. Their long, spindly legs, which continue to grow throughout their lives, help them navigate the deep ocean floor. Despite their formidable appearance, Japanese Spider Crabs are considered docile and are not active predators.
Other Noteworthy Large Crabs
While the Japanese Spider Crab reigns in leg span, other crab species are notable for their substantial size.
Coconut Crab
The Coconut Crab (Birgus latro) is the largest terrestrial arthropod, weighing up to 9 pounds (4.1 kg) with a leg span of about 3 feet (1 meter). Found on tropical islands in the Indian and Pacific Oceans, these crabs climb trees and crack open coconuts with powerful claws.
Tasmanian Giant Crab
The Tasmanian Giant Crab (Pseudocarcinus gigas) is among the heaviest crabs, with males reaching up to 39 pounds (17.6 kg) and a carapace width of up to 18 inches (46 cm). These crabs inhabit deep waters off Southern Australia and are characterized by males having one significantly oversized claw.
Alaskan King Crabs
Alaskan King Crabs (Paralithodes camtschaticus), particularly the Red King Crab, are also large. Some males weigh up to 28 pounds (13 kg) and have a leg span of 5 feet (1.5 meters). These crabs live in the cold waters of the North Pacific and are highly valued for their meat.