Alaskan King Crab

There are three species of King Crab fished commercially in Alaska, the Red King Crab, the Blue King Crab, and the Golden King Crab. A fourth species, the Scarlet King Crab, is also found in Alaskan waters, but is rare and does not support a commercial fishing industry. All four species belong to the overall super-family, Lithodoidea, which houses 113 living species overall.

Golden King from Calacademy.com

King crabs have five pairs of legs. The back pair are much smaller then the rest, and are usually hidden in the crab's carapace (body). They serve an important function during the mating season however, as females use them to tend to the embryos that she keeps under her tail, and they males use them in the fertilization process. The middle three sets of legs are used for walking, and the final set, that which is closest to the front of the body, sports pincers. In most crabs, the right claw is substantially larger than the left.

Like most animals, the King Crab grows larger as it ages. However, its carapace does not grow with it. As they age, the crabs must molt and grow new shells (which are made primarily of calcium). This molting process happens much more often when they are juveniles, and less when they are adults and have more or less plateau'd in size. King Crabs can live 25-30 years, and crabs that make it to those ages can be as many as five feet in leg span. King Crabs feed on all sorts of small marine life, including each other. They are preyed upon by fish, octopuses, and otters.

Red King from Alaska Fisheries Science Center

The Red King Crab is the most harvested of the Alaskan King Crabs. Crab fishing is also one of the most dangerous of all professions, with fatalities over 20 times greater than the average U.S. rate. The amount of danger involved in the Alaskan King Crab Industry has led to the creation of the Discovery Channel series, Deadliest Catch.