How to Tell if a Blue Crab is Dead or Alive

Before you cook crabs, it’s important to know which crabs are alive, and which are not. Crabs that die before you cook them taste mushy, flavorless, and sometimes make you sick.

So, how can you tell the difference? You know a crab is dead if its body is limp, mouth hangs open, and fins are unresponsive. An alive crab would scurry around and pinch anything that comes near it.

Believe it or not, there are a few techniques to easily check if a crab has died. Let’s go over each one.

3 Ways to Check if a Blue Crab is Dead

Let’s say you get back from your crabbing trip with a basket full of crabs. Once duped on the lawn, some try and scurry away, while others just sit there.

My first thought would be, “What a shame, that crab is dead.”

But just wait, that crab may still be alive.

Quick Note: Don’t try these techniques if the crab is showing any sign of life. You don’t want to get pinched!

The first way to check is to pick up the crab. Pinch the back end of the crab, with your thumb on the back of its shell and your fingers on its bottom.

If you raise the crab off the ground and its legs, claws, and fins all hang limp, the crab may be dead. If it starts to squirm or tries to pinch you, the crab is ready for the steamer.

The next step you should take is to check the crab’s mouth. With your free hand, open its mouth to see if it shuts. Just pull down on its little mouth fold and see how it reacts. If it hangs open or was hanging open in the first place, the crab has most likely died. If the mouth snaps shut, the crab is good to cook.

If you REALLY want to be sure, theres another test.

Holding the crab with one hand, locate the crab’s two back fins. They will always be opposite of the crab’s two claws.

Use your free hand to pull back on the fin’s joint closest to the body. Gently pull it away from the crab.

If its fins don’t pull back into place, the crab is officially dead.

If you have a Dungeness crab, do the same but with their smallest leg. If it does not pop back into place, it’s dead.

Should You Eat a Dead Blue Crab?

You should not cook or eat a dead blue crab. Once a crab dies, bacteria takes the opportunity to spread and make its meat mushy and flavorless.

Not only does it taste terrible, it can make people sick. It’s best to avoid eating dead crabs.

The only time I would eat a dead crab is if it was stored in a very cold environment, like a freezer or cooler. At least then the bacteria growth was slowed.

Personally, I wouldn’t eat it if it has been dead for more than an hour or two, even if was in a cooler or on ice.

How to Prevent Crabs from Dying

There are a few methods to preserving live blue crabs before cooking. If you do it right, you’ll end up with very few dead crabs, leaving plenty to throw in the steamer.

My go to strategy is keeping blue crabs in a cooler. It’s simple to do and very effective.

First, find a cooler with a plug/drain. We’re going to line bottom of the cooler with about 3 inches of ice. Cover the ice with a thin towel , this will lower the shock of cold ice and prevent your crabs from dying.

Now all you need to do is open the plug to let the melted ice drain away, and you’re ready for your crabs. Spread them evenly on the towel and avoid stacking them on top of one another. This will keep crabs alive for days at a time as long as there’s plenty of ice and fresh air in the cooler.

I made a 2000 word article explaining how to properly store and care for Blue Crabs. If you want to learn more methods to keep blue crabs alive, check it out: How to Keep Blue Crabs Alive and Well.

Related Questions

How can you tell if a blue crab has gone bad?

You can tell if a crab has “gone bad” if it’s dead, has a foul odor, or shows visual signs of decay or bacteria growth. I recommend only eating crabs that look clean and healthy.

Can you freeze blue crabs?

You can freeze blue crabs for weeks at a time after you clean the crustacean of its carapace (top shell), all of its guts, mouth, and lungs.