Emerald Crab – Natural Bubble Algae Control

Struggling with Bubble Algae in your reef aquarium? Meet the Emerald Crab, one of nature's most popular algae-eating clean-up crew members!

Known for its beautiful emerald-green coloration, strong claws, and fascinating scavenging behavior, the Emerald Crab is a popular addition to established saltwater reef aquariums.

One of its biggest benefits is its ability to eat nuisance Bubble Algae (Valonia), helping control unwanted algae growth on live rock and aquarium surfaces.

Emerald Crabs also consume other types of algae, leftover food, and organic debris, making them useful members of a marine aquarium clean-up crew.

Why Choose an Emerald Crab?

• Natural Bubble Algae Control: Known for consuming nuisance Bubble Algae (Valonia).

• Algae Grazer: Helps remove certain types of algae from live rock.

• Beneficial Scavenger: Consumes leftover food and organic debris.

• Beautiful Green Coloration: Adds a unique appearance to your aquarium.

• Clean-Up Crew Favorite: A popular choice for established saltwater aquariums.

Care Information

• Scientific Name: Mithraculus sculptus

• Common Names: Emerald Crab, Emerald Mithrax Crab

• Care Level: Easy to Moderate

• Temperament: Semi-Aggressive / Opportunistic

• Reef Safe: Generally Yes, with caution

• Recommended Tank Size: 20+ Gallons

• Maximum Size: Approximately 2.5 Inches

• Diet: Omnivore / Algae Grazer

• Temperature: 72–78°F

• Specific Gravity: 1.023–1.026

• pH: 8.1–8.4

• Origin: Caribbean / Western Atlantic

• Activity: Primarily Nocturnal

Feeding Recommendations

Emerald Crabs naturally graze on nuisance algae, including Bubble Algae, while also scavenging for leftover food.

Supplement their diet with dried seaweed (Nori), algae wafers, sinking marine pellets, and occasional meaty foods when natural food sources are limited.

Important Care Note

Although Emerald Crabs are widely used for natural Bubble Algae control, individual feeding behavior varies, and complete algae removal is not guaranteed.

Larger or underfed individuals may occasionally pick at corals, snails, or other small aquarium inhabitants. Provide adequate food and monitor compatibility.

Maintain stable water parameters, acclimate carefully, and avoid copper-based medications.

Specimen Information

You will receive one healthy Emerald Crab per unit ordered.

Actual size, coloration, and markings may vary.

Help keep your reef aquarium cleaner naturally with the Emerald Crab — a popular ally against unwanted Bubble Algae!