Both snow crabs and king crabs are omnivores, live in cold waters, and are popular targets for fisheries. However, that’s where most of their similarities end. These two species look, and often act, very differently. Let’s look at what makes each of them unique.
Image credit: Totti (left), The Children’s Museum of Indianapolis (right)
Main Differences Between Snow Crabs and King Crabs
- Size: Snow crabs are much smaller in size. The leg span of adult snow crabs is less than 3 feet (90 cm), while the leg span of king crabs is around 5 feet (150 cm).
- Weight: Male snow crabs can weigh up to roughly 4lb (1.8 kg). King crabs can weigh up to 24lb (10.9kg).
- Appearance: Snow crabs have four pairs of long walking legs. King crab legs are thicker, and only three pairs are walking legs; the last pair that is hidden underneath their carapace is smaller and is used in reproduction.
- Habitat: While both snow crabs and king crabs can be found in the northern parts of the pacific ocean, snow crabs typically live further north and can also be found in the North Atlantic and the Arctic oceans.
- Fisheries: Both species are known to be popular seafood choices; however, king crabs have a shorter harvesting season and are much more expensive due to their limited availability.
- Protection against predators: Snow crabs tend to burrow into mud or sand to hide from predators. On the other hand, some king crabs have developed an interesting defensive strategy when they group together in great numbers and use their claws to protect each other from all directions.
- Lifespan: Snow crabs are believed to live up to 20 years, while king crabs can reach around 30 years.
We’ll explore these differences and exciting facts about these creatures below.
What is a Snow Crab?
Snow crabs, also known as queen crabs or spider crabs, are subarctic crustaceans. There are two main species of snow crab—Chionoecetes Bairdi and Chionoecetes Opilio—and they differ in size. While Opilio is smaller, it is also more abundant. Scientists believe snow crabs can live up to 20 years.
Appearance
The shell of the snow crab, known as a carapace, is round and flat without any spikes. The color of snow crabs changes as they mature. They start off red-brown with an almost white underbelly, and as they grow, their color gradually fades to olive brown with a yellowish underbelly.
Their protective shells do not grow, so as the snow crabs get bigger, they have to shed the old carapace and grow a new one. This process is called molting, and crabs do it multiple times throughout their life. It can take about two months until their new shell hardens completely; during this time, they are especially vulnerable to predators.
Snow crabs have four pairs of long slender walking legs and one pair of claws. Males can be almost double the size of females, as their carapace can grow as wide as 6 inches (15 cm). Their maximum leg span is approximately 35 inches (90 cm), and their average weight is between 2 and 4lb (0.9-1.8 kg).
Habitat
As their name suggests, snow crabs are coldwater species that thrive in temperatures from -1 to 7 °C, which is 30 to 44.6°F. So it is no surprise that they inhabit the frigid seas of the North Atlantic and North Pacific oceans.
In fact, according to NOAA Fisheries, snow crabs can live as far north as the Beaufort Sea in the Arctic Ocean. They can be found off the coast of Canada, Maine, Alaska, Russia, Norway, and even Greenland.
Grown snow crabs can live deeper than 1000 feet (300m) and prefer soft ocean bottoms, such as sand and mud. Smaller crabs seek shelter in shallower waters.
Diet
Snow crabs are foraging omnivores, meaning they eat both plants and meat. They do not pass out on any food that comes their way, but their favorite snacks are shrimp, starfish, sea urchins, worms, large zooplankton, ocean quahog, sea snails, sponges, and anemones or small fish, such as capelin. They can also eat other crabs or marine algae.
When they move to greater depths, they pretty much become scavenging bottom feeders that feed on detritus (organic waste that fell to the ocean floor, such as dead animals, scales, etc.) but also on other bottom feeders that they happen to find.
Threats
Since snow crabs don’t do well in even remotely warm water, one significant threat they face is the warming of the ocean. Other dangers are the destruction of their habitat with bottom trawling, heavy fishing, or ocean acidification.
Their natural predators are mainly seals, sea otters, octopuses, squids, and other carbs. A variety of fish (like halibut, skate, or cod) also prey on snow crabs, especially when the crabs are molting. Snow crabs sometimes burrow into mud or sand to hide from their predators.
What is a King Crab?
King crabs are species of large crab. Their life expectancy is somewhere between 20 and 30 years. There are dozens of different species of king crabs; however, 3 of the main species we will primarily focus on are the red king crab, the blue king crab, and the smallest of the three, the golden (brown) king crab. These crustaceans are otherwise known as Alaskan king crabs and are often referred to as Alaskan colossal king crabs due to their large size.
Appearance
They are not called colossal crabs for nothing. The weight of an Alaskan king crab averages around 8lb (3.6kg), but it can easily exceed 20lb (9kg). Its carapace can grow up to 11 inches (28 cm) in length. The leg span of a grown male is about 5 feet (150 cm).
King crabs have three pairs of short thick walking legs, one pair of claws, and one more pair of back legs that are hidden underneath their carapace. Males use this pair of small back legs to transfer sperm, while females use it to care for the eggs in their abdominal pouch.
The king crab’s hard spiky carapace is effective at protecting it from potential predators. Alaskan king crabs can be either brown, dark red, or bluish in color, depending on the species.
Habitat
Alaskan king crabs enjoy the cold temperatures of the North Pacific. This means they can be found throughout the North Pacific as far south as Japan or British Columbia. Some of their main hotspots are the Bering Sea and adjacent waters, especially along the coast of the Aleutian Islands and in Bristol Bay, or the Gulf of Alaska and Kodiak Archipelago. Other species, such as southern king crabs, live in the cold waters of the southern hemisphere, like off the coast of southern Chile or Argentina.
In winter, king crabs come to shallow waters of or near the intertidal zone, where they molt, mate, and hatch embryos. Then in spring, they migrate offshore to waters sometimes deeper than 1,800 feet (550 m) to feed.
Diet
King crabs are omnivores. Juveniles mostly feed on algae and plankton, but the crabs become more carnivorous as they grow.
Larger crabs enjoy a range of invertebrates, including worms, sea urchins, snails, clams, mussels, barnacles, sea stars, sand dollars, and brittle stars, but they can also feed on fish. Moreover, red king crabs can be cannibalistic. In deep waters, they mostly rely on scavenging around for food.
Threats
One of the main threats for king crabs is ocean acidification, as it could cause their calcium shells to dissolve. Like snow crabs, king crabs are also a popular seafood delicacy, making them vulnerable to overfishing.
However, there are some fishing regulations in place to protect both species. In fact, the Alaska Department of Fish and Game has canceled the 2022/23 snow crab and red king crab seasons after discovering both populations crashed.
The king crabs are particularly vulnerable to predators when they are still small or when they are molting and mating. They can be preyed upon by fish, such as cod, sculpins, halibuts, and yellowfin soles, or by octopuses and sea otters.
To protect themselves from predators, red king crabs stack up on top of each other and use their claws to protect each other’s backs, so to speak. This defensive strategy is called podding.
FAQs
Why is king crab more expensive than snow crab?
King crabs can only be harvested from late fall to early winter. Snow crabs have a longer harvesting season (from early summer to late October/November), making them more available and, therefore, cheaper than king crabs. Another reason why king crabs are more expensive is that they are similar in flavor to lobster meat.
Do king crab and snow crab taste different?
Both species are known to have delicious meat with a sweet flavor. Snow crabs taste somewhat briny, while king crabs are popular for their lobster-like flavor. King crab meat has a different texture; it is more tender. King crabs also have more leg meat, as their legs are thicker than snow crab legs.
Why is there a shortage of king crab?
In recent years there’s been a limited supply of both king and snow crabs. Alaska had to cancel the 2022/23 snow crab and king crab harvesting seasons because the crab stocks were too low. As for why this happened, some experts point fingers at marine heat waves, while others suggest it is the result of heavy fishing and bottom trawling.
Snow crab vs king crab: Which one is bigger?
King crabs are much bigger than snow crabs. They can weigh over 20lb, while snow crabs tend to weigh less than 4lb. King crabs also have thicker legs than snow crabs.
