What crabs eat sea urchins?

There aren't many crab species that specifically eat sea urchins. Here's why and what crabs *do* eat:

* Sea urchins are tough: They have a hard, spiny shell that makes them difficult to crack open.

* Their defense: Sea urchins also have venomous spines that can deter predators.

However, some larger crabs, particularly those with powerful claws, can overcome these defenses:

* Stone crabs: These crabs are known to crush sea urchins with their strong claws.

* King crabs: Similar to stone crabs, king crabs have powerful claws and may occasionally eat sea urchins.

* Other crabs: Larger, more aggressive crab species, like spider crabs and blue crabs, may also opportunistically prey on sea urchins if they're available and accessible.

More common crab food:

* Other invertebrates: Crabs are generally opportunistic omnivores, so they primarily eat smaller crustaceans, mollusks (clams, snails), worms, and algae.

* Carrion: Crabs will also scavenge on dead animals.

Important Note: While some crabs *can* eat sea urchins, it's not a staple part of their diet. Their main food sources are usually easier to access and less defensively equipped.