King crabs are among the largest crustaceans in the ocean, known for their impressive dimensions. Their substantial size contributes to their status as a highly sought-after seafood globally. They inhabit cold, deep waters, primarily in the North Pacific Ocean and adjacent seas.
Measuring King Crab Dimensions
The size of king crabs is assessed using several measurements: carapace width, leg span, and overall weight. The carapace refers to the hard upper shell covering their body. Carapace width can reach up to 11 inches (28 cm). Leg span, measured from the tip of one leg to the tip of the opposing leg, can be up to 5 feet (1.5 meters), with some records indicating nearly 6 feet (1.8 meters). Their weight can also be substantial, with specimens weighing up to 24 pounds (10.9 kg), though the heaviest recorded individual was approximately 28 pounds (12.7 kg).
Size Variations Among King Crab Species
While all king crabs are large, their dimensions vary among species.
The Red King Crab (Paralithodes camtschaticus) is the largest species. Red King Crabs can weigh up to 24 pounds, with males often exceeding females in size, and have a leg span of up to 5 feet. Their carapace width can range from about 5.9 to 11 inches (15-28 cm).
Blue King Crabs (Paralithodes platypus) can also be substantial, with some individuals reaching up to 18 pounds (8.2 kg) in weight. Blue King Crabs are smaller than Red King Crabs. They are found in cold waters of the North Pacific and Bering Sea.
Golden King Crabs (Lithodes aequispinus), also known as Brown King Crabs, are the smallest of the three main king crab species. These crabs average between 5 to 8 pounds (2.3-3.6 kg) in weight. Golden King Crabs have notably thinner legs compared to their red and blue counterparts.
Biological Factors Influencing King Crab Size
Several biological and environmental factors contribute to the size of king crabs. Their long lifespan, which can extend between 10 to 30 years, allows for prolonged growth. King crabs inhabit cold, deep-water environments, which can influence their growth rates. The colder temperatures lead to a slower metabolism, which in turn can support larger body sizes over time.
Molting is an essential process that enables king crabs to grow. Since their hard outer shell, or exoskeleton, does not expand, crabs must periodically shed it to increase in size. During this process, the crab absorbs water, causing its body to swell and crack the old shell, allowing it to back out. The frequency of molting is higher in younger crabs and decreases as they mature, with adult males molting less regularly than females. Abundant food sources in their deep-sea habitats also provide the necessary energy and nutrients for their growth.