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
A friendly guide, not veterinary advice. For anything about your pet's health, ask your vet.
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
Owner questions the things everyone asks
How often should I feed my Three Stripe Damselfish?
Feed your Three Stripe Damselfish small amounts once or twice daily. Furry Diary's starting plan suggests feeding every day. For exact amounts, check the food label and ask your vet.13 Furry Diary plan
What does a Three Stripe Damselfish eat, and what should it never eat?
This omnivore enjoys meaty foods, plant-based foods, and flakes. As for what to never feed, it's best to avoid anything not designed for marine fish; ask your vet for a safe list.13
How much space does a Three Stripe Damselfish need?
Your Three Stripe Damselfish needs a marine or reef aquarium of at least 30 US gallons (about 115 liters). Provide plenty of hiding spaces like branching coral or rockwork.312
What temperature, light or water does a Three Stripe Damselfish need?
Keep the water at 22 to 26°C, pH 8.1 to 8.4, specific gravity 1.020 to 1.025, and alkalinity 8 to 12 dKH. For lighting, a standard reef light cycle works; ask a good breeder for details.312
How often should I clean a Three Stripe Damselfish's home?
Clean the glass weekly, test the water weekly, and do a 10-20% water change every two weeks. Also top up evaporation daily with fresh RO water, as Furry Diary's plan suggests. Furry Diary plan
Can a Three Stripe Damselfish live with others?
Yes, it can live with other fish of moderate temperament, but it becomes territorial as an adult. Provide plenty of space and hiding spots to keep everyone happy.213
How long does a Three Stripe Damselfish live?
Your Three Stripe Damselfish typically lives 5 to 6 years with good care.12
Can I handle a Three Stripe Damselfish?
It's best not to handle your fish; it can cause stress and injury. If you must move it, consult an aquatic vet for safe methods.
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Furry Diary's own starting care plan. A friendly guide, not a vet's advice.
You might also like
Domino Damselfish
Blue DamselfishLike what we are building? Buy Archy a bone.
All of this is free for everyone, with a source on every fact, and it will never show annoying ads. It was a big job to build, so if it helped you, buy Archy a bone. Any amount is lovely, and no is a perfectly fine answer too.
Archy is our Australian Cattle Dog and chief taste tester. Tips go to 4V3D OÜ, the small family studio behind Furry Diary.
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 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
- VCA Animal Hospitals: Feeding times and frequency for your dog vcahospitals.comused for owner questions
- ASPCA: Dog grooming tips aspca.orgused for owner questions
- ASPCA: Cat grooming tips aspca.orgused for owner questions
- ASPCA: People foods to avoid feeding your pets aspca.orgused for owner questions
- RSPCA: What to feed your rabbit rspca.org.ukused for owner questions
Checked 2026-09-30. Text is written in our own words from these sources.