Emerald Crabs are small green crabs that are excellent for helping control macro algae. In the wild they are mostly herbivores, but in the aquarium, they will eat all types of foods. Great for removing hair algae, and caleurpa, they tend to hang out on rocks until its feeding time. Reef Safe. These sometimes come in a red coloration as well.
Emerald Crab (Mithraculus sculptus)