Tanner crabs are commercially significant crustaceans found in the cold waters of the North Pacific. They are a popular seafood choice, appreciated for their distinct flavor and texture. This article explores their physical traits, natural environment, and how they compare to similar species.
Identifying the Tanner Crab
Tanner crabs belong to the genus Chionoecetes and are often called spider crabs. They have a round, flattened carapace, which can be brown and rough or bumpy for species like Chionoecetes bairdi. They possess four pairs of slender walking legs and a pair of claws, roughly the same size as their legs, equipped with narrow, curved pincers.
The underside of a Tanner crab is pinkish-orange to cream. Males are generally larger than females. The common name “Tanner crab” often refers to Chionoecetes bairdi, while other species within the genus, such as Chionoecetes tanneri (grooved Tanner crab) and Chionoecetes angulatus (angle Tanner crab), also exist.
Habitat and Life Cycle
Tanner crabs thrive in the cold, nutrient-rich waters of the North Pacific Ocean, including the Bering Sea and the Gulf of Alaska. Their geographical range extends from the Kamchatka Peninsula in the west to Bristol Bay, Alaska, in the east, and as far south as Hokkaido, Japan, and Oregon in the eastern Pacific. These crabs typically inhabit depths ranging from 50 to 500 meters, preferring soft, sandy, or muddy bottoms where they can burrow.
They grow by molting, shedding their shells. Young crabs molt frequently, with the period between molts gradually lengthening as they age, eventually molting once a year by age three. Reproduction occurs with females typically mating in the spring, after which they incubate numerous eggs under their abdominal flap for 12 to 15 months. Larvae hatch and swim freely for a few months before settling to the bottom.
Tanner Crab vs. Snow Crab
Tanner crabs and snow crabs are often confused due to their similarities and overlapping common names. While some Tanner crabs are marketed as “snow crab,” they are distinct species: Chionoecetes bairdi (Tanner crab) and Chionoecetes opilio (snow crab). A notable difference lies in their size, with C. bairdi generally being larger, weighing between 2 to 4 pounds, compared to C. opilio which typically weighs 1 to 2 pounds.
Tanner crabs have a slightly firmer texture and a mild, sweet flavor. Snow crabs are known for their sweet, tender, and succulent meat. Although they are distinct species, C. opilio and C. bairdi can interbreed, leading to hybrid individuals in certain regions of the Bering Sea and North Pacific. Their legs also show subtle differences, with snow crab legs being notably longer and thinner than those of C. bairdi.
Tanner Crab in the Seafood Market
Tanner crabs are commercially important in the seafood industry, particularly in Alaska, where a major fishery targets them. They are primarily harvested using pot fishing methods, similar to those used for king crab, with pots typically baited with chopped herring. Its sweet, tender meat and delicate texture make it a prized seafood.
Tanner crab meat is versatile for various culinary preparations, including steaming, grilling, or incorporating into dishes like bisques. While often sold as sections or clusters, Tanner crab landings are typically less than those of snow crab, yet they are considered a premium product.