Crabs

Green Emerald Crab - Mithrax sculptus
Green emerald crabs are questionable additions to reef tanks. While primarily algae eaters, they have been known to capture small fish and pick at coral polyps. They typically don't grow larger than 3 inches. The larger the tank, the safer they tend to be due to increased grazing area.

Naked Hermit Crab - Clibinarius tricolor
A common tri-color blue leg hermit crab captured on camera just before it tried on a new shell. These funny-looking critters hide their skinny bodies in shells, which is why this photo of a 'naked' hermit is unusual.

Red Leg Hermit Crab - unknown species
This red hermit crab was sold as a scarlet hermit but unlike true scarlet hermits, it doesn't have the characteristic yellow face. Generally not a fan of hermit crabs in reef tanks due to their diet of small crustaceans, worms from the sand, and even snails.

Unidentified Decorator Crab
This decorator crab is masters of camouflage - it's nearly impossible to locate on the rock and some people have trouble even finding it in the picture. The crab decorates itself with pieces of its environment to blend in perfectly with its surroundings.
