Three-Stripe Damsel
Dascyllus aruanus
Also known as Humbug Damsel, Whitetail Dascyllus
Care at a glance
- Temperature
- 75–81°F (24–27°C)
- pH
- 8.1–8.4
- Adult size
- 3.5 in (9 cm)
- Minimum tank
- 29 gal (110 L)
- Temperament
- Aggressive
- Social behavior
- Social
- Swim level
- Middle
- Difficulty
- Beginner
- Breeding
- Medium
- Rarity
- Very common
- Reef safe
- Reef safe
- Origin
- Indo-Pacific reefs
- Family
- Pomacentridae
Overview
Three-Stripe Damsels are tough, fast-acclimating fish that rarely get sick, which is a big reason they show up so often in beginner setups. Juveniles are fairly tolerant of tankmates, but they get noticeably bossier with age, staking out a patch of rock and chasing off anything that swims too close, including their own kind if the tank is too small. They leave coral and sessile invertebrates alone, so they are a safe pick for a reef tank as long as tankmates can hold their own ground. Feed a mix of frozen mysis or brine shrimp, marine flake, and some algae-based food to round out the diet.
In the wild
Lives on shallow Indo-Pacific reef flats and lagoons, where small groups shelter within the branches of a single Acropora or Pocillopora coral head. It rarely strays far from that cover, so the aquarium needs live rock arranged with real branching structure or crevices rather than open swimming space. A 110 liter (30 gallon) tank is the accepted minimum for one fish or a small group.
Good to know
Dascyllus aruanus is a protogynous hermaphrodite, so an individual can change from female to male, and each coral colony typically holds a harem built around one dominant male. The group settles onto its coral head as larvae and defends it as shared territory for life, with a size-based pecking order among members. Females scatter demersal eggs onto cleared rock near the coral, and the male fans and guards the clutch until it hatches a few days later.
Did you know
The bold black and white bands that give this fish its Humbug nickname can wash out to a dull gray overnight or under stress, then brighten back up again by morning.
Where to buy
Some links may not be the exact species or variety.
- LiveAquaria Freshwater and saltwater fish, inverts and corals
- Saltwaterfish.com Marine fish, corals and inverts shipped overnight
- Biota Captive-bred marine fish, corals and clams shipped direct
…or ask your local fish store.
Appears in
Saltwater fish · Beginner fish · Reef-safe fish · Beginner saltwater fish
Keeping Three-Stripe Damsel?
Track water tests, reminders and stocking fit.
Related species

Four-Stripe Damsel
Dascyllus melanurus3.1 in (8 cm)29 gal (110 L)75–81°F (24–27°C)
Domino Damsel
Dascyllus trimaculatus5.5 in (14 cm)55 gal (210 L)75–81°F (24–27°C)
Neon Damselfish
Pomacentrus coelestis3.5 in (9 cm)29 gal (110 L)75–81°F (24–27°C)
Blue Damsel
Chrysiptera cyanea3.1 in (8 cm)29 gal (110 L)75–81°F (24–27°C)
Fiji Blue Devil Damsel
Chrysiptera taupou3.1 in (8 cm)29 gal (110 L)75–81°F (24–27°C)
Barberi Clownfish
Amphiprion barberi3.5 in (9 cm)30 gal (115 L)75–81°F (24–27°C)
