What coral crab is this?

[SamuelTan]

Saw a few of them at Aquastar, size of a 10cent coin.

[Terryz_]

Zebra crab... Also know as urchin crabs, feed on urchin feets...

[puppet]

Zebrida adamsii "Zebra Thorn Crab"

The Zebra Thorn Crab (Zebrida adamsii) is known as an "urchin crab" as it is found living on the spines of sea urchins. It has a striking brown and white stripes coloration and a spiky shell. The last two legs are hook shaped to help it hold onto the urchin.

These crabs stay very small, under about an inch in shell diameter (not including legs). They will often feed on small meaty foods like brine shrimp but may eat some soft corals and polyps as well. Some references also report that these crabs will feed on the tissue and tubed feed of the urchin in which they host, leaving "naked spots" on the urchin.

taken from http://www.thatpetplace.com/pet/prod/253971/product.web

[SamuelTan]

Ahh i see interesting thanks! Isn't it consider a pest then?