Why Does This Crab Have an Extra Claw?

posted: 08/17/15
by: Danny Clemens

A world-famous Chesapeake Bay crab appears to be sporting an extra appendage, according to a photo shared on Reddit over the weekend:

View post on imgur.com

Although it's easy to assume the worst -- the Chesapeake Bay has been plagued with pollution and sanitation issues in recent years -- an astute commenter pointed out that it's not completely unheard of for crabs to grow an extra set of pinchers.

"Arthropods go through molting stages and if they are damaged it can sort of throw off their system creating something odd like this tiny claw. Because crabs can regenerate their claws occasionally there is a mix-up and instead of re-growing a claw it ends up growing a completely separate claw during a molt," explains Reddit user Alantha.

In 2013, a crab with a similarly deformed crab was discovered near Cornwall, England. A local aquarium official gave a similar explanation for the crab's strange claw, chalking it up to a biological anomaly.

H/T Azula

Learn more about crustaceans:

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