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Can a Dungeness Crab Break Your Finger?

Dungeness Crab Break Your Finger
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Whether or not you’ve worked with the Dungeness crab commercially or gathered it up in your Alaskan backyard at home, you’ve probably looked at the size of their pinchers and wondered what they were capable of. What would happen if your finger was caught?

The Dungeness crab is able to exert some of the highest forces of any recorded animal in any muscle, which is approximately 104-137lbs at least. This is not enough poundage to break a finger bone with gradual compaction as a Dungeness crab would apply to a finger.

Keep reading to learn more about what the Dungeness crab is capable of, how to hold one, what to do if you get caught by the claw, and more.

Do Dungeness Crab Claws Have The Force To Break A Finger?

To answer this question, we should take a look at the purposes of their pinchers, the average size of a Dungeness crab, and the reputation of their strength.

Dungeness crabs use their claws for two reasons

  1. Tearing apart their prey
  2. Self-defense

Their claws were made to kill, but what exactly were they made to kill? 

The diet of the Dungeness crabOpens in a new tab. consists of snails, clams, sea urchins, worms, muscles, and others. Because most of the creatures on the menu have tough shells, they need powerful pinchers to break through them. 

A freshwater smooth clam’s shell can withstand the compaction force of 3265 ± 1046 (1068−5831)Opens in a new tab. newtons, which is only 0.9lbs or 1.12 lbs of force. Meanwhile, saltwater mollusks, which the Dungeness crab would eat, have shells made to withstand the high pressures on the ocean floor. So a crab’s pinchers need to be able to exert a much greater amount of force than 1 lb to crack the shells. 

According to biologist Carin BondarOpens in a new tab., the Dungeness crab’s claw has produced some of the highest forces measured in any animal for any muscle. The claw is also lined with little white ridges that concentrate the force applied so that the force they exert on your finger – in the words of biologist Dr. Bondar – is,

“equivalent to a person standing in stiletto heels and putting all their weight on one heel.”

To put this into greater perspective, the average weight of an adult white female is between 104-137lbs.

The size of the crab is also important because the bigger the crab is, the more power it will have, and the more likely it will be able to break your finger. The average crab has a carapace (wide back) 25cmOpens in a new tab. or 10″ long, but it can be larger. Isn’t this enough to say the Dungeness crab can break your finger? Not necessarily.

How Much Force Does It Take To Break Your Finger?

While a Dungeness crab can apply the same force as the weight of an average adult woman (which is impressive!), it takes at least 1500 newtonsOpens in a new tab. or 337.21 lbs of force to fracture a finger bone. 

Does this mean they can’t break your finger? That would be an unsafe assumption considering size and aggression are two factors to consider with crabs. The total amount of force they can apply has not been documented. 

If you are ever caught in the clasp of the Dungeness crab, you can tell if your bone has been broken or fractured by these signs:

  1. You experience immediate pain. Be aware fractures will have sharper pain than breaks.
  2. You can still somewhat move your finger but with dull pain
  3. Bruising and swelling occur after 5-10 minutes
  4. Your finger stiffens up and feels numb

You might have heard it only takes 5-8lbs of force to break a finger, which is entirely possible. The difference between the two numbers is the acceleration of the force applied. If you were running and slammed your finger against a hard object, it would take less weight to break your finger than something slowly applying pressure, like a crab claw.

The Best Way To Hold A Crab Without Getting Pinched

While a Dungeness crab may or may not have the power to break your finger or slice it off, being pinched by one will still be extremely painful, especially if the crab has just been in the water and at its full strength.

So before you can go out to catch these giant crustaceans, you need to know how to handle one without getting pinched. 

Dungeness crabs are highly armored in hard and somewhat spikey shells on their backs and legs. You obviously can’t reach for a crab face-on because that’s where the claws are, and the crab can see you directly. 

You also can’t go for the left or right sides to try to grab a leg because the legs are sharp, and the pinchers can reach you anyway. And don’t even think about grabbing the top of the back. The pinchers reach up there too. 

The best way to properly hold the Dungeness crab is to come from behind the crab and grab the two rear fingers simultaneously. In this method, your hand or finger is far from the pinchers.

Experienced fishermen and women can manage to grab a crab from the front of the claws that are already pressed against the body. Nevertheless, this isn’t advised for individual non-commercial fishers because you will most likely face the crab in defense mode with the claws up and ready. 

Can the Moon Phases Affect a Dungeness Crab’s Behavior and Ability to Pinch?

The moon phases and surf fishingOpens in a new tab. are known to impact a Dungeness crab’s behavior and ability to pinch. When the moon is full or new, crabs may be more active and aggressive, leading to increased pinching behavior. Conversely, during quarter moons, they may be more passive and less likely to pinch.

What to Do If Your Finger Gets Caught In Crab Claws

When a crab of any species snaps at your hand and fingers, it’s always for self-defense. Since they have no intention to eat you, they want to distract you with pain to release them so that they can try to make an escape. So, as long as you are not holding onto them, they should pinch and release.

What if you are holding them, or what if they refuse to let go? Then you need to set them down on the shore so that you don’t lose the crab and wait for them to release your finger. On your own, you are not going to get your finger out of the death claw. Once your hand is free, you can try again to pick up the crab properly. 

If you are with a friend, they might be tempted to try to help you by pulling the claw open, but the safest and easiest way to get your finger out is to wait for the crab to let you go. 

One Last Thing

While the Dungeness crab’s ability to break your finger bones is a mute point because of the pain, you will feel without your bones breaking. It’s always good to have the threat possible in the back of your mind. 

It’s true that people have gotten their fingers caught and made it out without serious harm, but there are a number of factors that influence the crab’s strength. If they’re in a weaker state, they won’t have the same power they would in prime condition. 

Zaldy G.

I love feeling the cool ocean spray every time I hit the beach with a rod and a bucket of bait. I love the thrill of feeling bites on my line whenever I hook a big one. And I especially love the pride that comes with cooking a fresh catch and sharing it with my friends and family. Thank you for stopping by. Let's go catch some fish!

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