Not furry, but we like them anyway.
Three Stripe Damselfish
Dascyllus aruanus
Also called Humbug damselfish, Whitetail dascyllus, Banded humbug
From Indo-Pacific: from east and north of the Lombok Strait to the Line, Marquesas and Tuamotu islands, north to southern Japan and south to New Caledonia12
At a glance the quick version
FishBase lists a maximum reported age of 6 years; Wikipedia notes full size is reached by the end of year two
Looks how to spot one
Small, deep-bodied damselfish
A crisp black-and-white fish: a white body crossed by three bold black bands, a white tail and a white spot between the eyes. Most adults are about 6 cm, with a maximum near 10 cm.231
Personality what they are like
A feisty, territorial damselfish as an adult, but it leaves corals and invertebrates alone and fits well with other fish of moderate temperament.32
Daily activity how busy a day looks
Active by day, hovering above its home coral and darting into the branches for cover.12
Grooming and care the hands-on bits
Easy care. Provide plenty of hiding spaces, ideally branching coral or rockwork it can treat as home.32
Home where they are happiest
A marine or reef aquarium of at least 30 US gallons (about 115 L). Saltwater at about 22 to 26 °C, pH 8.1 to 8.4, specific gravity 1.020 to 1.025, dKH 8 to 12. Reef safe. In the wild it lives on shallow lagoon and reef flats, usually 1 to 10 m deep, around branching Acropora coral.312
Food basics what goes in the bowl
An omnivore. Wild fish eat zooplankton, small bottom-living invertebrates and algae. In aquariums feed meaty foods, plant-based foods and flakes.13
Company who they like around
Lives in groups over a single coral head, sometimes around 30 fish, with a pecking order based on size. In aquariums it does best with plenty of space and hiding spots.213
The story where it all began
Carl Linnaeus described it in 1758 as Chaetodon aruanus, making it one of the earliest described damselfish; it was later moved to Dascyllus. Its hardiness earned it a reputation as a classic starter marine fish, and it has been reared in captivity.21
Fun facts for the dinner table
- 1
It acts like a gardener for its home coral: its waste supplies nutrients that help the coral, and studies link this to corals coping better with heat.2
- 2
Females can lay up to about 2,000 eggs per batch, and males court them with a 'signal jump'.2
- 3
Females tend to choose males that have recently spawned with other females, a behaviour called mate copying.2
- 4
Eggs hatch after 3 to 5 days, and the male guards them until then.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 Three Stripe 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
You might also like
Domino Damselfish
Blue DamselfishLike what we are building? Buy us a coffee.
The breed atlas is free for everyone, with a source on every fact, and it will never show ads. If it helped you, a small tip keeps the research going. Any amount is lovely, and no is a perfectly fine answer too.
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 [email protected] and we will fix it.
- FishBase: Dascyllus aruanus, Whitetail dascyllus fishbase.seused for distribution, size, depth, diet, social groups, breeding, max age, IUCN status
- Wikipedia: Dascyllus aruanus en.wikipedia.orgused for colours, groups, coral relationship, breeding, lifespan, taxonomy
- LiveAquaria: Three Stripe Damselfish liveaquaria.comused for aquarium care, tank size, water parameters, temperament
Checked 2026-09-30. Text is written in our own words from these sources.