Emerald crab
A small Caribbean crab that eats bubble algae in reef aquaria.
Last updated
Mithraculus sculptus, commonly known as the emerald crab or green clinging crab, is a small marine crab in the family Majidae. It is native to tropical waters of the Caribbean Sea and Gulf of Mexico, where it inhabits a variety of environments including back reef areas. This species is notable in the aquarium trade for its ability to consume nuisance bubble algae.
Scientific classification
- KingdomAnimalia
- PhylumArthropoda
- CladePancrustacea
- ClassMalacostraca
- OrderDecapoda
- SuborderPleocyemata
- InfraorderBrachyura
- FamilyMithracidae
- GenusMithraculus
- SpeciesMithraculus sculptus
Named by (Lamarck, 1818)
Close relatives
Other species of Mithraculus with a Codexery entry.
- Banded clinging crab Mithraculus cinctimanus
Sources: Wikipedia taxobox: Mithraculus sculptus (CC BY-SA 4.0) · order, family and genus agree with WoRMS AphiaID 421990 (CC BY 4.0)
How big is it?
Largest length in the source, 0.04 m, next to a 1.8 m person.
Diagram: drawn by Codexery, schematic shapes to scale (not a likeness). Length: Wikipedia: Mithraculus sculptus
Where the emerald crab has been recorded
Each dot is a place where the species has been observed and reported (930 records, half-degree grid) — not a modelled range. 47 inland records left out (institution coordinates). 3 isolated far-off records not drawn.
Map: drawn by Codexery. Data: GBIF occurrence search (records CC0 / CC BY) · Natural Earth basemap (public domain) · place coordinates: Wikipedia (CC BY-SA 4.0)
Quick Facts
- Genus
- Mithraculus
- Species
- sculptus
Facts from the source article.
Background
The emerald crab has a flat, shiny green carapace that is longer than it is wide, finely sculpted with whitish material on its projections. Its large chelae (claws) are also green, spoon-shaped, and tipped with white, while the walking legs are paler, hairy, and often encrusted. It grows to about 4 cm in length. This species ranges from the Bahamas and southern Florida to northern Brazil, at depths down to about 54 meters.
It is found in varied habitats but may be most abundant in back reef environments. It is often seen among branches of corals such as Porites furcata and on turtle grass (Thalassia testudinum). Mithraculus sculptus is largely nocturnal, hiding in caves, crevices, and under rocks during the day. It is a scavenger that also feeds on algae.
It tolerates both high and low temperatures and can withstand strong currents by clinging to the substrate with its legs. When threatened it often hides beneath the extended tentacles of the sun anemone (Stichodactyla helianthus).
More in Shrimp, Crabs & Urchins
Elsewhere in Reef Aquarium Species
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Mithraculus sculptus (CC BY-SA 4.0).
- Classification: the source article's taxobox; order, family and genus checked against WoRMS, the World Register of Marine Species (CC BY 4.0).
- Occurrence records: GBIF (CC0 / CC BY). Basemap: Natural Earth (public domain).
- Word definitions: the , each quoted from its Wikipedia article.
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