What Is the Lifespan of an Alaskan King Crab?

Known for its succulent flesh and large legs, the king crab is a favorite at seafood buffets and sushi bars worldwide. Although the average crab that is destined for the dinner plate weighs in at as much as 10 lbs., this resilient and fascinating creature begins its life no larger than the head of a pin.

  1. Species

    • There are three species of commercially viable Alaskan king crab: red, blue and golden. Found at a depth of approximately 90 feet, the red king crabs are the largest of the three, and live in the shallowest water. The blue and golden varieties of king crab reside at 200 and 300 feet respectively. The scarlet crab is a fourth variety of Alaskan king, but it is too small to be commercially important.

    Mating

    • King crabs become sexually mature at 5 to 6 years of age and undergo elaborate courtship rituals before mating. Known as "hand shaking," the couple faces each other in a mating dance that may last up to seven days. The female then lays between 150,000 and 400,000 eggs which she will incubate for nearly a full year before they hatch. It is necessary for the king crab to reproduce so vigorously as very few of the hatchlings will survive to adulthood.

    Juvenile Crabs

    • The newly hatched king crabs are known as zoea and are a miniscule 1/25th of an inch in size. They remain this size for approximately two to three months, making them easy prey for a wide variety of sea creatures. Those that survive to the next stage mature to postlarva, at which time they begin to take on the appearance of adult crabs. During the course of the next several years, the little crabs will molt repeatedly as they grow. Although solitary as adults, young crabs between the ages of 2 and 4 years will live together in pods that may contain thousands of members, relying on their numbers to increase their chances of survival.

    Adults

    • A male king crab may only be legally harvested when it is sufficiently large and sexually mature. The minimum size that is legal for capture is 6.5-inch width at the carapace, or the exoskeleton covering the major body section known as the cephalothorax. Typically a crab of this size is between 7 and 10 years of age. It is illegal to harvest female king crabs.

    Predators

    • As juveniles, king crabs are the prey of a wide variety of species including but not limited to Pacific cod, Pacific halibut, sockeye salmon, skates and even large king crabs. As adults, the main threat to the king crab is the commercial fishing industry. Although many species of crabs were overfished initially, efforts to stabilize king crab populations are proving successful. Should a crab evade capture, it can live in the wild for as long as 25 years.