The Royal Gramma is a small basslet split vividly into magenta-purple at the front and golden-yellow at the rear.
Hardy, peaceful toward unrelated fish, and reef-safe, it is a good colourful beginner marine fish.
It darts among rockwork and often hangs upside-down beneath ledges.
It comes from Caribbean reef caves and appreciates plenty of hiding spots.
A well-fed Royal Gramma is shy at first but soon becomes confident, claiming a favourite cave and defending it with mostly harmless bluster against passing tankmates.
Housing
A cycled 110L (30 gal) tank with abundant live rock, caves, and overhangs lets it feel secure.
Maintain salinity 1.024-1.026, temperature 24-27°C (75-80°F), pH 8.1-8.4, and nitrate under 20 ppm.
A lid is essential, as they readily jump from open tanks.
Provide line-of-sight breaks with rock so it can establish a home base without stress.
The more caves and crevices available, the bolder and more visible it becomes, since it always wants an escape route close at hand.
Diet
The Royal Gramma is a carnivore that in the wild eats zooplankton and small crustaceans.
In the aquarium offer frozen mysis and brine shrimp, finely chopped seafood, and a sinking marine pellet, fed once or twice daily.
Most specimens feed readily within days of settling in.
A varied meaty diet keeps the purple and gold colours strong.
Feed modest amounts to avoid fouling the water, and make sure faster tankmates do not take all the food first.
Health
Royal Grammas are hardy and relatively disease-resistant in stable water.
The main risks are marine ich and bacterial infections following stress, poor water quality, or aggression from tankmates or a rival Dottyback.
Quarantine new arrivals and keep nitrate low and parameters steady.
Watch for hiding, refusing food, or white spots as early warning signs.
A secure, cave-rich tank reduces stress and keeps this basslet healthy for years.
Temperament
Peaceful toward unrelated species, the Royal Gramma is territorial mainly around its chosen cave, where it bluffs and posts largely harmless threats.
It is reef-safe and ignores corals and invertebrates.
Keep one per tank unless the system is very large with widely separated territories, as they fight their own kind and the similar-looking Royal Dottyback.
With peaceful tankmates and good cover it is a confident, characterful resident.
A good fit for
Beginners wanting vivid colour
Peaceful community reef tanks
Smaller marine setups
Keepers who enjoy cave-dwelling behaviour
Common mistakes to avoid
Keeping multiples in small tanks (fighting)
Confusing it with the aggressive Dottyback
No caves or hiding spots causes stress
Open-top tank leads to jumping
Is your enclosure big enough?
Minimum volume110 litres (29 US gallons)
CompanyMust be housed alone. Best kept singly; territorial with own kind
In a reef, stability matters more than any single target number. A parameter moving fast does more damage than a parameter sitting slightly off.
Go now
Any detectable ammonia or nitriteWater change now with matched, mixed and aerated saltwater. Stop feeding. Directly toxic, and a marine system has less margin than a freshwater one.
Now
Temperature or salinity has moved sharplyCorrect slowly, over hours, not minutes. Check the heater and the top-off. The speed of the change does the damage. Correcting fast repeats the injury in the other direction.
Now
Rapid gilling, or a fish hanging in the flow breathing hardIncrease aeration and check temperature and salinity. Warm water holds less oxygen, and a heater failure shows up here first.
Now
Today
White spots, or a fine dusting like icing sugarIdentify which parasite before treating. Most reef tanks cannot be treated in place. The two common parasites look similar and need different handling; velvet can kill a tank in days.
Today
Corals closed for more than a day, or receding tissueTest alkalinity first, and compare it against the last reading rather than a target. Unstable alkalinity is the most commonly cited coral killer, and a swing shows up in the trend, never in a single point.
Today
A new fish added without quarantine now looks unwellRemove it to a separate system today if you can. Nearly every wipeout in a reef tank traces back to a skipped quarantine.
Today
Quarantine every new animal, including corals and inverts. It is the single practice that separates a reef that lasts from a reef that restarts.
This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it — and the time to find one is before you need one.
What it really costs
Setup, monthly, first year and across a whole life, itemised and with the electricity worked out from the actual wattage. Published figures for the same animal disagree by a factor of four, so the calculator shows ranges rather than picking one.
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