Side-by-side

Emerald Crab vs Sally Lightfoot Crab

Tank size, water parameters, diet, temperament, reef-safety, and which species fits which keeper. All data cross-checked against vetted Fast Aquatics vendor records.

Reviewed by the Fast Aquatics husbandry team

Emerald Crab

Mithraculus sculptus
Min tank size10 gallons
Care difficultyintermediate
DietOmnivore
TemperamentPeaceful
Reef-safen/a
Temperature74-80°F
Full Emerald Crab care guide →

Sally Lightfoot Crab

Percnon gibbesi
Min tank size30 gallons
Care difficultybeginner
DietOmnivore
TemperamentPeaceful
Reef-safen/a
Temperature74-80°F
Full Sally Lightfoot Crab care guide →

Which is better for...

Use caseRecommended
Best for beginnersSally Lightfoot Crab
Best for nano tanks (under 30 gallons)Emerald Crab
Hardiest in established tanksSally Lightfoot Crab

Emerald Crab pros and cons

Pros: Adult size fits 10 gallons tanks well. Easy to feed on standard pellet/flake/frozen diets. Reef compatibility: n/a.

Cons: Requires intermediate-level husbandry experience. Sourcing premium specimens can require waiting for charter breeder drops.

Sally Lightfoot Crab pros and cons

Pros: Hardier than Emerald Crab for first-time keepers. Adult size fits 30 gallons tanks well. Easy to feed on standard pellet/flake/frozen diets. Reef compatibility: n/a.

Cons: Sourcing premium specimens can require waiting for charter breeder drops.

Compatibility - can they live together?

Mixing Emerald Crab and Sally Lightfoot Crab in one tank depends on adult size overlap, territory needs, and water-chemistry match. Peaceful/Peaceful pairing means both species share similar temperament so direct fights are rare, but resource competition (food, territory, hiding spots) is common. Both species need water parameters within 74-80°F and 74-80°F. If keeping together, introduce the more peaceful species first by 2-4 weeks, provide multiple hiding spots, and feed at separate ends of the tank.

Sourcing and price expectations

Both Emerald Crab and Sally Lightfoot Crab sell at three tiers on Fast Aquatics and competitor sites. Budget tier (pet-store grade): $5-50. Mid-tier (LFS or online vendor stock): $25-200. Premium tier (named lines, charter breeders): $100-2,000+. Captive-bred or aquacultured specimens cost more upfront but ship healthier than long-supply-chain wild-caught. Browse Emerald Crab and Sally Lightfoot Crab live availability on Fast Aquatics for current vendor pricing with carrier-tracked Buyer Protection on every order.

Frequently asked questions

Is Emerald Crab or Sally Lightfoot Crab better for beginners?

Sally Lightfoot Crab is the better choice for beginners. Emerald Crab requires intermediate-level experience.

What is the minimum tank size for Emerald Crab vs Sally Lightfoot Crab?

Emerald Crab requires 10 gallons minimum, while Sally Lightfoot Crab needs 30 gallons. Both should be planned around adult size, not juvenile size.

Can Emerald Crab and Sally Lightfoot Crab be kept in the same tank?

Compatibility depends on adult size, temperament, and territory overlap. Both are typically considered peaceful (Emerald Crab) and peaceful (Sally Lightfoot Crab) species. Always quarantine both, introduce the more peaceful species first, and monitor for aggression in the first 30 days.

Which costs more, Emerald Crab or Sally Lightfoot Crab?

Pricing varies by source and grade. Budget specimens from pet-store-grade vendors run $5-50 for both species. Mid-tier specimens run $25-200. Premium grades (charter breeders, named lines) reach $100-2,000+. Browse Fast Aquatics for current market pricing.

Which is more reef-safe?

Emerald Crab is rated n/a and Sally Lightfoot Crab is rated n/a. For mixed-reef setups, prefer the species rated reef-safe; species rated "with caution" or "no" need careful tankmate planning.

What do Emerald Crab and Sally Lightfoot Crab eat?

Emerald Crab: Omnivore. Sally Lightfoot Crab: Omnivore. Diet match-up matters for compatible feeding schedules and nutritional needs.

More comparisons

Browse the full comparison library for more side-by-side species breakdowns. See full care guides for Emerald Crab and Sally Lightfoot Crab for the complete husbandry breakdown of each.