Emerald Crab (Mithraculus sculptus)

Max Size: 2 1/2 inches
Diet: Omnivore
Temperament: Semi-Aggressive
Reef Compatible: With Caution. May eat soft polyps
Minimum Tank Size: 20 gallon

The Emerald Crab is known for its scavenging abilities and is highly regarded for its capability to consume uneaten meaty foods and different types of nuisance algae. One unique feature of the Mithraculus sculptus is that it feeds on bubble algae, making it an essential part of aquarium cleaning. The Emerald Crab can be distinguished by its flat, shiny green body and furry legs. It is originally found in the reefs of the Caribbean and is a nocturnal creature that typically seeks shelter in caves or rubble during the day.

In a home aquarium, the Emerald Crab requires a well-established environment with a lot of hiding places and rockwork. Once comfortable in its surroundings, the crab will emerge from hiding to forage on algae during the day. It is vital to ensure that there is sufficient food available for the Emerald Crab. Dried seaweed and meaty foods such as chopped shrimp, along with high-quality pellet fish food, are commonly added to supplement their diet.

Inadequate food supply may cause the crab to turn to corals, small fish, or invertebrates as an alternative food source. However, when properly fed, Emerald Crabs are tolerant of other tank mates and are suitable for a reef environment. It is important to note that the Emerald Crab, like other invertebrates, is not tolerant of copper-based medications or inconsistent water parameters.