King crab can reach 11 inches in width (of carapace) and 10.5 to 24 pounds of weight. Some species have leg span of 6 feet. Males are generally larger than females.
King crab has large body covered with thick, armoured shell. It has five pairs of legs. First pair is transformed into unevenly-sized pincers (right claw is larger) that are used for feeding.
Fifth pair of legs is small and specialized for transfer of sperm cells during the mating and for cleaning of fertilized eggs. Most species of king crab are dark red, golden-orange or brown-bluish colour
Aside via body size, males and females can be distinguished via abdomen that is wide and fan-shaped in females and narrow, triangular in males.
King crab cannot swim. It moves on the ocean floor using its long legs. King crab can survive 20 to 30 years in the wild.
King crab breathes via gills. It has blue-colour blood due to hemocyanin, blood pigment that contains copper.
King crab is a carnivore. Its diet is based on the worms, clams, mussels, snails, sea stars, sea urchins, sand dollars, barnacles, crabs and fish.
Natural enemies of king crabs are fish such as Pacific cod and halibut, octopuses and sea otters. King crab is solitary creature outside the mating season
King crab migrates from deep toward the shallow waters (breeding grounds) at the beginning of the spring. King crab can walk distance of 100 miles during the annual migrations. It usually travels one mile per day.
Female carries thousands of fertilized eggs under her broad abdomen. Small larvae emerge from the eggs 12 months after mating. They swim and feed on phyto and zooplankton during the first few months of their life. Larvae molt frequently and slowly transform into non-swimming juveniles that settle on the sea floor.