Blue Porcelain Crab
The Blue Porcelain crab (Petrolisthes galathinus) will consume bits of food that are in your water column, capturing them with their webbed appendages that they wave throughout the day. An attractive reef safe crab often found in groups.
The name "Blue Porcelain Crab" is a bit of a misleading trade name. The color is closer to a gray and purple and it is variable between specimens. The pictured crab is similar in appearance to the one you will receive.