QUICK STATS

Care Level: Easy
Diet: Carnivore / Planktivore
Temperament: Peaceful, Territorial Around Its Cave
Reef-Safe: Yes
Venomous/Toxic: No
Approximate Purchase Size: 1-2"
Approximate Max Size: Around 3"
Recommended Tank Size: 30 Gallons or Larger

ROYAL GRAMMA

The Royal Gramma (Gramma loreto), also known as the Royal Gramma Basslet, is a classic reef-safe saltwater fish known for its bold purple front half, bright yellow rear half, and striking black eye stripe. It brings a lot of color to an aquarium without needing a massive tank, advanced care, or a dramatic feeding ritual involving three frozen foods and a prayer.

Royal Grammas are popular because they are hardy, peaceful with most tank mates, and excellent choices for reef aquariums. They often spend time near caves, ledges, and rockwork, darting in and out of shelter throughout the day. Once established, they can become surprisingly visible and confident, especially if they feel secure in their chosen cave.

This species is considered reef-safe and should not bother corals or most invertebrates. It may become territorial around its preferred cave or hiding spot, especially toward similar-shaped fish, other grammas, or small basslets. Peaceful does not mean defenseless. This fish may be small, but it absolutely has “get off my porch” energy.

Note: Image is a representation of what to expect. The fish you receive may vary slightly in size, color, markings, purple/yellow intensity, and overall appearance.

AQUARIUM REQUIREMENTS

AQUARIUM SIZE

A minimum tank size of 30 gallons or larger is recommended for a Royal Gramma. This species stays relatively small, usually around 3 inches, but still benefits from stable water quality, live rock, and enough territory to feel secure.

For pairs or multiple Royal Grammas, a larger aquarium is strongly recommended. They can become territorial with their own kind, especially in smaller tanks where every cave apparently becomes contested real estate.

HABITAT RECOMMENDATIONS

Royal Grammas do best in established aquariums with live rock, caves, overhangs, and secure hiding places.

Aquascaping: Provide live rock with caves, ledges, crevices, and shaded areas. Royal Grammas often choose a favorite cave or overhang and spend much of their time nearby.

Substrate: Sand, fine aragonite, crushed coral, or bare-bottom systems can all work. This species does not depend heavily on the substrate.

Rockwork: Live rock is strongly recommended. It provides shelter, territory, biological filtration, and natural hunting areas.

Caves & Overhangs: Provide multiple hiding places, especially if housing with active or semi-aggressive fish. Royal Grammas are much more confident when they have a secure retreat.

Tank Cover: A tight-fitting lid is recommended. Royal Grammas are not the most notorious jumpers, but startled fish still have a long history of making terrible vertical decisions.

WATER PARAMETERS

Royal Grammas are generally hardy once established, but they still need clean, stable marine conditions. “Beginner-friendly” does not mean “compatible with whatever chemistry disaster is currently trending.”

Temperature: 72-78°F
pH Level: 8.1-8.4
Salinity: 1.020-1.026 specific gravity
Ammonia, Nitrite, and Nitrate: Ammonia and nitrite should remain undetectable. Nitrate should be kept as low as reasonably possible, ideally below 20 ppm.
Water Flow: Low to moderate flow is ideal. Provide enough movement to keep the aquarium oxygenated and move food through the water column, while still allowing calmer areas around caves and rockwork for resting.

DIET

Royal Grammas are carnivorous planktivores that naturally feed on small drifting foods, tiny crustaceans, and other meaty items. In aquariums, they usually accept a wide variety of frozen and prepared foods once settled.

PRIMARY DIET

Frozen Food: Offer mysis shrimp, enriched brine shrimp, cyclops, marine blends, finely chopped seafood, and other small frozen foods. We at Summit City Coral prefer frozen foods such as LRS Reef Frenzy and PE Mysis.

Prepared Foods: High-quality marine pellets, flakes, and prepared carnivore or omnivore foods can help provide balanced nutrition. Smaller food sizes are best.

Live Foods: Copepods, amphipods, live brine shrimp, blackworms, and other small live foods can help encourage feeding, especially in newly introduced or shy individuals.

Small Meaty Foods: Finely chopped clam, shrimp, squid, and other marine foods can be offered occasionally for variety. Avoid oversized foods unless you enjoy watching a basslet stare at dinner like it has been handed a legal contract.

FEEDING FREQUENCY

Feed small amounts 1-2 times per day. In community tanks, make sure food reaches the Royal Gramma before faster fish inhale everything like aquatic debt collectors.

COMPATIBILITY

Royal Grammas are peaceful with most community fish and work very well in reef aquariums. They may become territorial around caves or toward similarly shaped fish, but they are usually not aggressive enough to cause problems when housed properly.

COMMON TANK MATES

Fish: Clownfish, cardinalfish, firefish, gobies, blennies, peaceful wrasses, chromis, dwarf angelfish, anthias, tangs in larger aquariums, and other peaceful to semi-peaceful reef fish.

Avoid: Large predatory fish, overly aggressive dottybacks, aggressive damsels, triggers that may harass them, groupers, lionfish, hawkfish large enough to eat them, and any fish likely to bully or swallow them.

Similar Species: Use caution with other grammas, basslets, dottybacks, or similarly shaped cave-dwelling fish, especially in smaller aquariums.

Invertebrates: Usually safe with cleaner shrimp, hermit crabs, snails, urchins, and common cleanup crew animals. Very tiny crustaceans may be at some risk, because small meaty snacks do not receive diplomatic immunity in reef tanks.

Coral: Royal Grammas are considered reef-safe and should not bother soft corals, LPS, SPS, zoanthids, mushrooms, clams, or anemones.

BEHAVIORAL NOTES

Temperament: Peaceful overall, but may defend a favorite cave or section of rockwork.

Cave-Dwelling Behavior: Often chooses a cave, ledge, or overhang as a home base and stays nearby.

Hovering Behavior: May hover at odd angles near rockwork or under ledges. This is normal behavior, not the fish malfunctioning, despite what it may look like.

Reef Compatibility: Excellent for reef tanks. They generally ignore corals and most invertebrates.

Territoriality: May show aggression toward similar-shaped fish or other Royal Grammas, especially in smaller aquariums.

Visibility: May hide when first introduced but usually becomes more visible once comfortable.

Coloration: Typically shows a bright purple front half and yellow rear half, often with a black stripe through the eye. Color intensity may vary depending on stress, diet, lighting, and maturity.

Feeding Behavior: Usually accepts frozen and prepared foods readily once settled. Shy individuals may need food offered closer to their preferred cave.

Beginner Friendly: A strong choice for newer reef keepers when housed in a stable, established aquarium with peaceful tank mates.

Jumping: A tight-fitting lid is recommended. They are not the most jump-prone fish, but the floor remains undefeated.

ACCLIMATION PROCESS

This acclimation method helps reduce stress by gradually introducing the fish to your aquarium’s temperature and water chemistry.

1. TURN OFF THE LIGHTS & ATO

Turn off aquarium lights to reduce stress. If you have an Auto Top Off system, switch it off before starting acclimation.

2. FLOAT THE BAG

Float the sealed bag in the aquarium for 15-20 minutes to allow the temperature in the bag to equalize with the tank.

3. OPEN BAG, ADD FISH TO CONTAINER

Carefully open the bag and transfer the fish and shipping water into a clean bucket or container.

4. ACCLIMATE USING TANK WATER

Add 1/4 cup of tank water to the container every 5 minutes for 40 minutes.

5. TRANSFER FISH TO AQUARIUM

Once acclimation is complete, gently transfer the fish into the aquarium using a net or specimen container. Discard the shipping water. Do not pour shipping water into your aquarium.

6. REFILL THE AQUARIUM WITH SALTWATER

You may need to replace the saltwater removed during acclimation with fresh mixed saltwater.