The Emerald Crab is a reef safe crab that is best known for eating bubble algae. You do not need to have bubble aglae to keep these green crabs as they will eat all other type of algae including hair algae and bryopsis.
They are easily identifiable by their flat, shiny shell and green color. They are found in the reefs of the Caribbean and are mostly nocturnal. They can be found hiding among rock works or caves. Emerald crabs are opportunistic feeders that will also scavenge for uneaten food and detritus that lands in the rock work. They are tolerant and other crabs and fish and get along fine with other tank inhabitants. The Emerald Crab does not tolerate copper-based medications or fluctuating water parameters.