Not furry, but we like them anyway.
Domino Damselfish
Dascyllus trimaculatus
Also called Domino damsel, Threespot dascyllus, Domino
From Indo-Pacific: Red Sea and East Africa east to the Line and Pitcairn islands, north to southern Japan and south to Sydney; not found in Hawaii or the Marquesas12
At a glance the quick version
Looks how to spot one
Deep-bodied, rounded damselfish
A jet-black to grey fish with three white spots, one on each side and one on the forehead, like the dots on a domino. The spots can shrink or the forehead spot can be missing in some fish. Juveniles are black with bluish scale centres.213
Personality what they are like
A confident, territorial damselfish that holds its ground; retailers suggest keeping one per tank alongside fish that can stand up for themselves.3
Daily activity how busy a day looks
Active by day, swimming around coral heads and rocks it treats as home.12
Grooming and care the hands-on bits
Easy care. Give plenty of live rock for grazing and hiding, and choose tankmates that are not too small or too large and predatory.3
Home where they are happiest
A marine or reef aquarium of at least 30 US gallons (about 115 L) with moderate water flow and lots of rockwork. Water about 23 to 26 °C, pH 8.1 to 8.4, specific gravity 1.020 to 1.025. Reef safe. In the wild adults live in groups around coral heads and large rocks down to about 55 m.312
Food basics what goes in the bowl
An omnivore. Wild fish eat algae, copepods and other planktonic crustaceans. In aquariums offer meaty foods, algae and flake and pellet foods.123
Company who they like around
Wild adults form small groups; juveniles shelter with large sea anemones, sea urchins or branching coral. In aquariums usually kept singly.213
The story where it all began
Eduard Rüppell described the species in 1829 as Pomacentrus trimaculatus, and it is now placed in the genus Dascyllus. It has long been a popular aquarium fish, and young ones grow quickly in larger tanks.21
Fun facts for the dinner table
- 1
Its name comes from the three white spots that look like the dots on a domino tile.2
- 2
Young dominos live among the tentacles of large sea anemones, sometimes alongside clownfish, and leave once they mature.2
- 3
Domino damselfish use sounds to recognise members of their own species.2
- 4
The male guards and fans the eggs until they hatch.1
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 2021)1
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Domino Damselfish. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- FeedingSmall amounts once or twice a dayevery day
- Temperature checkevery day
- Salinity checkevery week
- Top-upTop up evaporation with fresh RO water, not salt waterevery day
- Water testevery week
- Water changeAbout 10 to 20% of the waterevery 2 weeks
- Glass cleanevery week
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at support@furrydiary.app and we will fix it.
- FishBase: Dascyllus trimaculatus, Threespot dascyllus fishbase.seused for distribution, size, depth, juvenile colour, diet, breeding, IUCN status
- Wikipedia: Dascyllus trimaculatus en.wikipedia.orgused for common names, pattern, anemone association, sounds, taxonomy
- Saltwaterfish.com: Domino Damsel saltwaterfish.comused for aquarium care, tank size, water parameters, temperament, diet
Checked 2026-09-30. Text is written in our own words from these sources.