Snow crabs are marine crustaceans that do not live in terrestrial snow. They are found exclusively in the ocean. As a type of crab, they are invertebrates with an exoskeleton, ten legs, and a segmented body.
Their True Home: The Deep, Cold Ocean
Snow crabs inhabit the deep, cold waters of the northern hemisphere. They are predominantly found in the North Atlantic, North Pacific, and Arctic oceans, with significant populations off the coasts of Alaska, Canada, Russia, and Greenland. These crabs thrive in water temperatures ranging from -1°C to 5°C, though they can tolerate temperatures up to 7°C.
Snow crabs reside on soft, muddy, or sandy seafloors, where they burrow for shelter and food. They are found at depths ranging from 20 meters (about 65 feet) to over 600 meters (about 1,970 feet) below the ocean surface. Adult females often congregate at depths between 60 to 120 meters, while larger adult males are more commonly found below 80 meters. The specific depth can depend on their life stage and seasonal movements, with juveniles sometimes found in shallower waters.
The Origin of Their Name
The name “snow crab” stems from several factors related to their environment and appearance. One primary reason is their habitat in extremely cold, near-freezing ocean waters. These crabs require water temperatures below 5°C to survive.
Additionally, the color of their cooked meat contributes to their name. When cooked, snow crab meat turns a bright, snowy white. Their association with the icy, northern regions where they are found reinforces the “snow” descriptor. The scientific genus name, Chionoecetes, literally translates to “snow inhabitant.”
Key Characteristics and Lifestyle
Snow crabs (Chionoecetes opilio) possess a small, rounded, and flat body, known as a carapace. Their shells range in color from light red to brown on top, with a lighter white or yellowish underside. They are characterized by ten long, slender legs, with claws on the front two pairs and the remaining four pairs used for walking. Male snow crabs can reach a carapace width of up to 150 millimeters, with legs extending to nearly one meter, and can weigh up to 1.4 kilograms. Females are generally smaller, with carapace widths ranging from 40 to 95 millimeters.
These crabs are omnivorous scavengers, feeding on bottom-dwelling invertebrates like other crustaceans, bivalves, and mollusks, as well as small fish and other seafloor debris. Snow crabs grow by periodically shedding their hard outer shell through molting, allowing them to increase in size. After molting, their new shell remains soft for several months, making them vulnerable to predators.