The King Crab, particularly the Red King Crab (Paralithodes camtschaticus), is recognized as a massive crustacean and a prized commercial catch. Found primarily in the cold, deep waters of the Bering Sea and the North Pacific, this creature represents the upper limit of size among commercially harvested crabs. Understanding the actual size of these animals requires looking beyond anecdotal reports to the statistical averages and specific biological metrics used by scientists and fisheries management.
Average Size and Weight of the Red King Crab
The Red King Crab provides the benchmark for size. An average male harvested in the Bering Sea fishery typically weighs around 6.4 pounds, though commercial catches frequently range between six and eight pounds. These commercially viable males possess a leg span that usually measures between three and four feet across. Females are noticeably smaller than males, rarely exceeding ten to eleven pounds, and are generally not targeted for harvest.
The size a crab reaches is directly related to its age and molting frequency. King crabs can live for 20 to 30 years, and they must shed their rigid exoskeletons to grow. Younger crabs molt several times a year, but as males mature, they may skip a molt and retain the same shell for one or two years. This slower, less frequent molting allows them to dedicate more energy to increasing in mass, resulting in the massive sizes seen in the oldest individuals.
Comparing the Three Main Species
While the Red King Crab is the most famous, two other species are commercially harvested: the Blue King Crab (Paralithodes platypus) and the Golden King Crab (Lithodes aequispinus). The Red King Crab is the largest species overall. Blue King Crabs are a close second in size, often displaying a wider carapace than the Red species and capable of reaching weights up to 18 pounds. They are sometimes marketed interchangeably with the Red King Crab due to their similar flavor and large size.
The Golden King Crab, also known as the Brown King Crab, is significantly smaller than its Red and Blue relatives. This species averages a weight of five to eight pounds, often half the maximum weight of the Red King Crab. Golden King Crabs are found in deeper waters and tend to have a lighter, less dense shell, differentiating them from the more robust Red King Crabs. The size difference directly influences the meat yield, making the Red and Blue species more sought after.
Record Holders and Maximum Potential
While a six to eight-pound crab is the industry standard, the maximum potential size of the Red King Crab is far greater. The largest scientifically documented male Red King Crab weighed up to 24 pounds, an immense specimen. Some historical reports suggest individual crabs have reached weights of 28 pounds, with a leg span stretching up to five feet from claw to claw.
These record-breaking dimensions result from the animal’s ability to survive for decades and its unique molting pattern. The largest males accumulate biomass over many molting cycles. The largest individuals typically inhabit areas outside of high-traffic fishing grounds, which allows them the necessary time to reach their full size without being harvested.
How King Crab Size is Measured
In both scientific research and commercial fishing, the size of a King Crab is not typically measured by its total weight or the span of its legs. Instead, the standardized metric is the dimensions of the carapace. Specifically, scientists and regulators use Carapace Length (CL) or Carapace Width (CW) to quantify a crab’s size for data collection and management.
Carapace measurements enforce minimum legal harvest limits, ensuring that only mature, large males are removed from the population. Minimum sizes are often set in terms of Carapace Width, such as 152 millimeters (approximately six inches), to protect younger, smaller crabs. This focus provides a consistent, repeatable measurement regardless of the crab’s condition or whether its legs are intact. The total weight and leg size marketed to consumers are secondary metrics derived from these primary carapace dimensions.