Three-Stripe Damsel

Dascyllus aruanus

Also known as Humbug Damsel, Whitetail Dascyllus

SaltwaterFish

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.

Appears in

Saltwater fish · Beginner fish · Reef-safe fish · Beginner saltwater fish

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