How big does Royal Gramma get?

Royal Gramma reaches an adult standard length of 7–8 cm (excluding the caudal fin). Size the tank for that, not for the juvenile you bring home — the difference is often several times over, and upgrading later costs more than buying once.

What water does Royal Gramma need?

24–27 °C, pH 8.1–8.4, 7–12 dGH, 7–9 dKH, specific gravity 1.023–1.026. That is only 3 °C wide, so stability matters more than hitting a particular number.

What is the smallest tank for Royal Gramma?

At least 60 L, and no shorter than 60 cm. That is the floor for long-term keeping, not for short-term survival: volume buys water stability and length buys swimming room, and neither substitutes for the other. It is not a schooling fish, so a single specimen or a pair is fine.

What is Royal Gramma like to keep?

Temperament: semi-aggressive. Difficulty: beginner. It occupies the middle and is carnivore. Reef safety is "Reef safe".

Can Royal Gramma be kept with its most common tank mate?

The checker returns "Not recommended together". Royal Gramma and Orchid Dottyback is a recorded conflict in this atlas. Predation, territorial fighting or conspecific aggression is the usual outcome, and a bigger tank does not change it.

G-01 / 49Marine

Royal Gramma紫背草莓

Gramma loreto · Grammatidae

Half purple, half yellow; hangs upside down in caves and is a live-rock favourite.

Illustration to come

G-01 / 49 · Royal Gramma Gramma loreto

SpecificationsFish atlas

Name: 紫背草莓
Scientific name: Gramma loreto
Family: Grammatidae
Origin: Tropical western Atlantic reefs
Adult size: 7–8 cm
Temperament: Semi-aggressive
Diet: Carnivore
Water level: Middle
Level: Beginner
Min. tank: 60 L
Min. length: 60 cm
Reef safe: Reef safe

Water requirementsMarine

Temp.24–27 °C

pH8.1–8.4

Salinity1.023–1.026 SG

Alkalinity7–9 dKH

Units: temperature in °C, hardness in German degrees (dGH / dKH), marine salinity as specific gravity at 25 °C, volume in litres. These are the values recorded for the species and do not follow the site unit switcher.

Keeping notes

1Often hides for days after introduction; do not rearrange rockwork looking for it.
2Conspecifics fight; keep one unless you have a bonded pair.
3Let it settle before adding boisterous fish that would suppress it.
4Eats small shrimp and planktonic crustaceans; shrimp fry may disappear.
5Reef safe; carnivore that keeps colour best on frozen brine and mysis.

Check a tank mate

Jump straight to the verdict for Royal Gramma against this one — no need to pick it again.

Recorded conflictOrchid DottybackPseudochromis fridmani→

Frequently asked questions

How big does Royal Gramma get?: Royal Gramma reaches an adult standard length of 7–8 cm (excluding the caudal fin). Size the tank for that, not for the juvenile you bring home — the difference is often several times over, and upgrading later costs more than buying once.
What water does Royal Gramma need?: 24–27 °C, pH 8.1–8.4, 7–12 dGH, 7–9 dKH, specific gravity 1.023–1.026. That is only 3 °C wide, so stability matters more than hitting a particular number.
What is the smallest tank for Royal Gramma?: At least 60 L, and no shorter than 60 cm. That is the floor for long-term keeping, not for short-term survival: volume buys water stability and length buys swimming room, and neither substitutes for the other. It is not a schooling fish, so a single specimen or a pair is fine.
What is Royal Gramma like to keep?: Temperament: semi-aggressive. Difficulty: beginner. It occupies the middle and is carnivore. Reef safety is "Reef safe".
Can Royal Gramma be kept with its most common tank mate?: The checker returns "Not recommended together". Royal Gramma and Orchid Dottyback is a recorded conflict in this atlas. Predation, territorial fighting or conspecific aggression is the usual outcome, and a bigger tank does not change it.