Common name: nodose clinging crab

General information

The Green Emerald Crab, scientifically known as Mithraculus coryphe, is a popular invertebrate in the marine aquarium hobby. These small crabs are prized for their vibrant green coloration and their appetite for algae, including bubble algae which can be problematic in reef tanks. They are a species of reef crab found in the warm waters of the Western Atlantic, including the Caribbean Sea and the Gulf of Mexico.

Care

Emerald Crabs are relatively easy to care for, provided they are kept in a well-established aquarium with plenty of live rock for grazing and hiding. They are known to be opportunistic feeders, so while they primarily consume algae, they may also feed on leftover meaty foods. It's important to ensure they have enough natural food sources in the tank, or they may turn to nipping at corals or small fish.

Reproduction

In the home aquarium, reproduction of Emerald Crabs is not commonly observed. In the wild, after mating, females carry the fertilized eggs on their abdomen until they hatch into larvae, which go through several planktonic stages before settling down and growing into adult crabs.

Symbiosis

While not known for any specific symbiotic relationships like those seen in clownfish and anemones, Emerald Crabs do contribute to the overall health of the reef tank by controlling algae growth and cleaning up detritus.

Habitat

Mithraculus coryphe is typically found in shallow reef environments where they can blend in with the surrounding rockwork and vegetation. They are adept at navigating the complex structures of coral reefs and are an integral part of the natural clean-up crew in their habitat.