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Royal grammas are peaceful toward most reef fish and make excellent community tank inhabitants. Their main compatibility issues are with their own species and with fish that share a similar body shape or coloration. This guide covers the best tankmates for royal grammas, what to avoid, and how to build a successful reef community around them.
The Ground Rules
- One royal gramma per tank in most systems. Royal grammas are territorial toward their own species and will fight in tanks that do not provide clearly separated territories.
- Avoid fish with similar body shape and coloration: Royal grammas may be aggressive toward fish that resemble them, particularly the royal dottyback (Pictichromis paccagnellae), which looks nearly identical but is significantly more aggressive. See our Royal Gramma vs Royal Dottyback guide.
- Reef safe: Royal grammas do not nip coral and are compatible with most reef invertebrates including shrimp, crabs, and snails.
- Quarantine all new additions for 4-6 weeks before adding to the display tank.
Good Royal Gramma Tankmates
Clownfish
Clownfish are one of the most compatible tankmates for royal grammas. They occupy completely different areas of the tank - clownfish stay near their host anemone or a fixed territory, while royal grammas occupy caves in the rockwork. The two species ignore each other in virtually all cases. A clownfish pair and a royal gramma is one of the most classic beginner reef community combinations. See our Clownfish Care Guide.
Blue Tang
Blue tangs and royal grammas coexist well. They occupy different areas of the tank and have no significant territorial overlap. The blue tang's active open-water swimming does not conflict with the royal gramma's cave-dwelling behavior. Note that a blue tang requires a 100+ gallon tank, so this combination is only appropriate in larger systems. See our Blue Tang Care Guide.
Gobies
Small gobies - watchman gobies, neon gobies, clown gobies - are excellent royal gramma tankmates. They occupy the bottom of the tank and are ignored by royal grammas. Neon gobies provide the additional benefit of cleaning parasites from other fish.
Firefish and Dartfish
Firefish and purple firefish are peaceful mid-water fish that coexist well with royal grammas. They occupy different areas of the tank and are not threatened by royal grammas. A tight-fitting lid is essential as both royal grammas and firefish are prone to jumping.
Cardinalfish
Banggai and Pajama cardinalfish are peaceful, slow-moving fish that coexist well with royal grammas. They are reef safe and do well in pairs or small groups. Their calm demeanor and different tank position make them compatible community members.
Chromis
Blue-green chromis are peaceful schooling fish that add movement to the mid-water column. They are reef safe, hardy, and ignored by royal grammas. Keep in groups of 5 or more for best results.
Wrasses (Reef-Safe Species)
Many reef-safe wrasse species are compatible with royal grammas. Fairy wrasses and flasher wrasses are peaceful and add striking color. Six-line wrasses can be aggressive toward smaller passive fish - monitor carefully if combining with a royal gramma in a smaller tank.
Dwarf Angelfish
Dwarf angelfish such as the flame angel and coral beauty are generally compatible with royal grammas in larger tanks. Monitor for coral nipping - some dwarf angelfish develop this behavior in reef tanks.
Tankmates to Avoid
Other Royal Grammas
Two royal grammas in a tank without clearly separated territories will fight. Keep only one per tank in most home aquarium setups. In very large tanks with extensive rockwork providing distinct cave territories, a mated pair may coexist, but this is not recommended for most setups.
Royal Dottyback
The royal dottyback (Pictichromis paccagnellae) looks nearly identical to the royal gramma but is significantly more aggressive. Do not keep these two species together. The dottyback will also harass other small, peaceful fish. See our Royal Gramma vs Royal Dottyback guide.
Aggressive Damselfish
Highly aggressive damselfish species such as three-stripe damsels and domino damsels will harass royal grammas and other peaceful tankmates. Avoid these species in any community reef tank with a royal gramma.
Large Predatory Fish
Lionfish, groupers, and large hawkfish may prey on royal grammas. At 3 inches, a royal gramma is small enough to be eaten by many larger predatory fish.
How to Introduce Tankmates
- Quarantine all new fish for 4-6 weeks before adding to the display tank
- Add the royal gramma before more aggressive species to allow it to establish territory first
- Introduce new fish after lights out to reduce territorial responses
- Observe closely during the first 48-72 hours for aggression
- Ensure adequate rockwork so each fish has its own territory