Emerald crab
Mithraculus sculptus · Mithracidae
Also known as Green mithrax crab
Beginner
Eats bubble algae and detritus; useful, but an underfed adult starts sampling corals.
- Minimum tank
- 40 L
- Temperature
- 24–27 °C
- pH
- 8.1–8.4
- Adult size
- 5 cm
- Group size
- 1+
Will it fit your tank?
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Sign in to check my tanksReef & marine husbandry
- Specific gravity
- 1.024–1.026
- Reef safety
- Reef safe with caution
- With corals
- Will pick at soft coral and zoanthids when hungry.
- With inverts
- May catch slow snails.
- Minimum in a mixed reef
- 40 L
- Minimum fish-only (FOWLR)
- 40 L
- Aggression
- Opportunistic at night.
- Feeding
- Offer nori if bubble algae runs out.
Care requirements
- Minimum tank volume
- 40 L
- Temperature
- 24–27 °C
- pH
- 8.1–8.4
- Hardness
- 8–12 dGH
- Lifespan
- 2–4 years
- Diet
- Omnivore — bubble algae, detritus, sinking pellets, nori.
- Care level
- Beginner
Origin & habitat
- Native region
- Caribbean
- Water type
- Saltwater
- Biotope
- Rocky reef crevices
- Natural conditions
- Stable salinity, plenty of rock.
Behaviour & stocking
- Temperament
- Semi-aggressive
- Minimum group
- 1 fish
- Swims
- Bottom
- Good tank mates
- TangsClownfishSnails
- Avoid
- Small sleeping fishDelicate SPS frags
Breeding & difficulty
- Breeding difficulty
- Advanced
- Sexing
- Females have a broader abdominal flap.
- Notes
- Not bred at home.
- Common ailments
- Moult failureCopper poisoning
