About Green Clinging Crab
Emerald crab — the hobby's go-to solution for bubble algae (Valonia) outbreaks. Reef-safe with caution: well-fed individuals leave fish and corals alone, but underfed ones will sample anything. Keep 1 per ~30 gallons.
Mithraculus sculptus, the green clinging crab or emerald crab, is a species of crab in the family Majidae. It is a dark green colour and is found in tropical waters in the Caribbean Sea. It is sometimes kept in reef aquaria.
Notes from the editors
What it looks like. Compact dark green crab with smooth shell and hairy legs. Adult carapace size ~1.5 inches.
In your tank. The hobby's go-to solution for bubble algae (Valonia) outbreaks. Well-fed individuals leave fish and corals alone; underfed individuals will sample sleeping fish, polyps, and small inverts.
Care notes. Reef-safe with caution. Keep 1 per 30 gallons. Supplement with leftover meaty food if there's no bubble algae problem to consume.
Sourcing and feeding. Wild-collected from Caribbean waters; widely available ($10–25). Omnivore — bubble algae preferred, leftover meaty foods.
Care info is a starting point, not a guarantee. Individual specimens, water chemistry, and tankmate dynamics vary. Verify against multiple sources and adjust to what you observe. See our terms & disclaimers.
Related invertebrates
Sources & attribution
- Taxonomy and accepted name from the World Register of Marine Species (WoRMS AphiaID 421990).
- Description content adapted from Wikipedia, available under CC BY-SA 4.0.
- Photo: (c) Sam Turner, some rights reserved (CC BY) · CC-BY (via iNaturalist or Wikimedia Commons).