CheckMyFishTank

Domino Damselfish care

Dascyllus trimaculatus · Saltwater · Beginner level care

Domino Damselfish, painted illustration

A hardy but aggressive damsel that gets large.

Smallest tank55 gallons
Adult size5 inches
Temperature76 to 80°F
pH8.1 to 8.4
GroupOne per tank
TemperamentAggressive
SwimsMiddle of the tank
Lives8 to 12 years
Watch for: Gets bossy with age and bullies tankmates, so avoid in peaceful tanks.

Feeding

Twice a day. A small pinch they finish in about 2 minutes, a little more for bigger fish. Marine pellets, frozen mysis, flakes.

Claims a territory and guards it.

Good tank mates

Fish that pass every check with Domino Damselfish in a 110 gallon tank: same water, overlapping temperature, nobody gets eaten and no bullies.

Bicolor BlennyBlue Devil DamselfishClark's ClownfishMidas BlennyOcellaris ClownfishOrchid DottybackPercula ClownfishRoyal GrammaSix Line WrasseSkunk Clownfish

Do not mix with

  • Green Chromis: Domino Damselfish is aggressive and will bully peaceful Green Chromis.
  • Firefish Goby: Domino Damselfish is aggressive and will bully peaceful Firefish Goby.
  • Purple Firefish: Domino Damselfish is aggressive and will bully peaceful Purple Firefish.
  • Banggai Cardinalfish: Domino Damselfish is aggressive and will bully peaceful Banggai Cardinalfish.
  • Pajama Cardinalfish: Domino Damselfish is aggressive and will bully peaceful Pajama Cardinalfish.
  • Yellow Watchman Goby: Domino Damselfish is aggressive and will bully peaceful Yellow Watchman Goby.
  • Neon Goby: Domino Damselfish is aggressive and will bully peaceful Neon Goby.
  • Yellow Clown Goby: Domino Damselfish is aggressive and will bully peaceful Yellow Clown Goby.

Questions

What size tank does a Domino Damselfish need?

At least 55 gallons. Adults grow to about 5 inches, so plan for the adult size, not the size at the store.

What temperature does a Domino Damselfish like?

76 to 80 degrees Fahrenheit, with a pH of about 8.1 to 8.4. A steady temperature matters more than hitting one exact number.

How many Domino Damselfish should I keep together?

Keep only one. Domino Damselfish fight their own kind.

What do Domino Damselfish eat?

Marine pellets, frozen mysis, flakes. Feed twice a day: a small pinch they finish in about 2 minutes, a little more for bigger fish.

Sources

Checked against these sources on 2026-11-10. When sources disagree we use the safer number.