With over 6700 different species, crabs are a delicacy for many creatures, including humans. Many people love to dine on this delicacy. That begs the question, why and how did humans decide to munch on these creatures that resemble spiders (an animal few would choose to eat). That may not be a question we can answer here. Instead, we will focus on what animals eat crabs, which are an important part of the food chain.
What Animals Eat Crab?
Since crabs live everywhere, in a wide variety of environments, they have a lot of natural predators. Some live in salt water, others in fresh water. Thus their enemies thrive in the water. Some crabs spend time on dry land, and have to beware of different types of predators. Newborn crabs, who do not have shells, are particularly vulnerable to becoming someone’s meal. In general, thought, the following animals love to dine on crab:
- Birds: There are many kinds of birds that eat crabs. Some of them stick to crab larvae. Others choose to eat smaller adult crabs. Some birds carry crabs high into the air, then drop them on boulders below. This cracks their shells, allowing access to the tender flesh inside.
- Fish: If these creatures of the water have powerful jaws that can crunch into a crab’s shell, they too will dine on these bottom feeding creatures.
- Mammals; Depending on ease of access, there are a variety of mammals that will make a feast of crabs. This includes raccoons, otters, and seals. If an animal like a raccoon just happens to be near the shore getting a drink of water, and there also happen to be crabs nearby, a crab will easily become the next meal.
- Other Crabs: Crabs are omnivores, which is beneficial to coral reefs and ocean floors. They keep things clean. However, this also means they eat anything, which includes larger crabs turning cannibal and dining on smaller crabs.
- Pistol Shrimps: While this may not be the most important crab predator, it shows how many creatures have become masters at finding ways around the hard shells that protect your average crab. Pistol shrimp shoot high-powered bubbles at crabs, knocking them unconscious. They then have more easy access to crab meat.
- Alligators: With their powerful jaws, there’s nothing to hold an alligator back from crunching into a crab or two if they are the easiest prey. Hatchling alligators in particular will feed on this tasty treat.
We’ve looked at a general list of some crab enemies. Specific creatures have more tendency to dine on crabs, depending on location and access among other things. We explore this more below.
Do Octopuses Eat Crabs?
Octopuses eat crabs in a truly grisly way. Since they don’t have the jaw capacity to crunch down on a crab shell, octopuses use venomous saliva to kill or paralyze their prey. Their sharp beaks can easily inject venom into their victims. How do they do this when a crab that has the protection of its shell? They inject the poison down the eye-stalk of the crab. The poison causes the crabs muscles to relax. This enables the octopus to have easier access into the shell, and dine on the tasty flesh inside.
What Kinds of Fish Eat Crabs in the Ocean?
The list of fish that feast on crabs regularly is long. It includes; American eels, striped bass, red drums, croakers, black drum, cobia, and even sharks. Crab larvae and juvenile crabs face danger from smaller fish, sea rays, and eels. When a crab is molting (shedding their shell because they need a larger one) it leaves them vulnerable to all of these fish, who can avoid the shell while having a delicious meal.
What Kinds of Birds Eat Crabs?
Coastal birds love to eat crabs, especially species like the blue crabs which live in coastal waters and tidal rivers. Birds will dine on larvae off shore. They eat young growing crabs on shorelines, and adult crabs in seagrass beds and marshes. Herons, egrets, seagulls, and diving ducks have been known to indulge in a crab-shaped treat. Seagulls go after crabs that get stuck in tide pools at low tide. They either smash them on the rocks or drop their crab victims from great heights to smash open their shells and gain access to their meat. Herons stab and crunch up the shells first, before swallowing crabs whole.
Do Turtles Eat Crabs?
What turtles eat depends on what kind of jaw it has, where it lives, and what food sources are available. Some turtles are strictly vegetarian, others are omnivores. Some species of sea turtles include crab in their diet. Loggerheads, with a massive head and strong jobs, are omnivorous when young but carnivores as adults. They can easily crush hard-shelled prey like crab. Olive ridley turtles and Flatbacks will eat anything, including crabs. Kemp’s ridley turtles, another carnivore, eats a variety of prey but show a preference for . . . you guessed it, crabs.
Do Jellyfish Eat Crabs?
Jellyfish are carnivorous, opportunistic, predators. This means that, while they don’t eat plant matter, they will eat anything they come across that fits into the small hole they call a mouth. This means that what they eat depends on the size of the jellyfish, and the size of the hole through which they feed. Unlike other predators, jellyfish aren’t exactly aggressive in their method of gathering food. Their poisonous tentacles paralyze food as it happens to float by, and eventually shorter tentacles help bring that food to their “mouths.” Some larger jellyfish do take a more active role, shooting a stinging thread towards their prey. This means that it tends to be the larger jellyfish that actually eat prey like crabs. If a crab should happen to touch one of it’s longer tentacles, the jellyfish will shoot its stinging thread. If it is successful knocking out or killing the crab, it will then try to get the food into its hole. Of course, if the jellyfish’s hole isn’t big enough, the crab may remain uneaten, but still dead.
While you would think that the shells might be a deterrent, the opposite is actually true. One thing that all predators of crabs have in common (including humans) is finding ways to either work around the shell, or actually eat it, in their desire for the flesh within.