Porcelain Anemone Crab


Some Porcelain Crabs look good enough to be made into porcelain collectables.  As the name rightly suggests, the porcelain crab is a delicate and fragile crab-like crustacean that sheds its limbs to escape predators.

The Porcelain Crab is not actually a true crab but that doesn’t make them any less interesting. Unlike true crabs, the porcelain crabs have long antennae. They have three pairs of walking legs, whereas true crabs have four pairs. In porcelain crabs, the fourth pair of legs are too small and are not visible, as they are held against their body. Their tails (or reduced abdomen) are kept folded under their body. When disturbed, they may use this structure as a paddle for swimming up and down.

Porcelain Anemone Crab Photo by Tom Gorman - Gorman Dive Adventures
Porcelain Anemone Crab Photo by Tom Gorman - Gorman Dive Adventures

The Porcelain Crab is common throughout the tropical oceans of the world, and has a flat, round body with two large front claws and pinchers.  Though they look formidable, these appendages are used during territorial fights with similar species, and not for predation. These delicately spotted crabs live in a symbiotic relationship with anemones. While the anemone offers shelter and protection to the porcelain crab, the latter keeps the anemone clean. It is said that these organisms compete with clownfish for establishing their territory in sea anemones.

Porcelain Anemone Crab and  Clownfish
Porcelain Anemone Crab and Clownfish

Did You Know?

  • Although a female Porcelain Crab is less than an inch long they are capable of carrying over 1600 eggs on their body at any given time (she must hide them everywhere!)
  • The Porcelain Crab is able to drop a claw or a leg if they feel threatened – Don’t worry, it will grow back
  • The large claws of this crab are simply used to defend their territory and don’t typically play a role in catching lunch
  • Porcelain Crabs live together in pairs typically found within or under rocks in nature
  • The Porcelain Crab constantly filters the water for planktonic food, but will also scavenge for larger meaty portions.
  • A female porcelain crab less than an inch long may carry nearly 1,600 eggs at a time (though most carry only around 600).
  • Up to 860 porcelain crabs have been found living in a 10-square-foot (one-square-meter) section of a mussel bed off Pacific Grove, California!
  • Porcelain crabs belong to family Porcellanidae, infraorder Anomura, and order Decapoda. These crustaceans are classified under 30 genera that have around 300 species.
Porcelain Crab

Unique Evolution

One of the most fascinating aspects of the Porcelain Crab is how they evolved. Okay, I understand that may sound like a weird thing to find fascinating but let me explain. The Porcelain Crab is the perfect example of a process called carcinisation. This fancy-named process occurs when a non-crab-like animal evolves into an animal that resembles a true crab. That’s right, the Porcelain Crab is not actually a “crab” as they are closely related to a creature known as the Squat Lobster (yes, this name makes me laugh as well).

Porcelain Anemone Crab

Count the Legs

One of the easiest ways to distinguish today’s featured animal from a true crab is by counting the number of walking legs they have. I will save you the time of counting, the Porcelain Crab only has three pairs of walking legs whereas true crabs typically have four. Since we are discussing the appearance for the Porcelain Crab, I might as well tell you that these interesting creatures are only about 15 millimetres (0.6 inches) in length and usually have nice coloration.  Considering their small size, it must be awfully difficult to count their legs – now I bet you are happy that I counted them for you!

Porcelain Crab

Stop, Drop and Roll

Sticking with their legs, these small appendages can play a large role in their defence strategy. Typically, the Porcelain Crab uses their small size to easily conceal themselves away from dangerous predators, however, if they find themselves caught between the proverbial rock and a hard place (i.e. a hungry predator) they are able to drop their claw or leg, which usually distracts their attacker long enough allowing them to scurry away. Luckily this appendage will regenerate over the next few days and the Porcelain Crab will carry on as if nothing happened. Okay, perhaps this little behaviour is the most fascinating aspect of this crab-like animal.


Source: Wildfacts, LiveAquaria, Monterey Bay Aquarium, Buzzle

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January 26, 2017 |

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