At a glance the quick version
Wikipedia gives 4 to 6 years or longer in aquariums and mentions up to 15 years
Looks how to spot one
Small, laterally compressed damselfish
A small, bright blue damselfish with a clear yellow tail. The yellow may spread onto the rear of the dorsal and anal fins, especially in fish from Papua New Guinea, but never onto the back or belly.23
Personality what they are like
Semi-aggressive but noticeably milder than most damselfish. Some individuals may guard space against their own kind or similar-sized fish, and males become protective while guarding eggs.32
Daily activity how busy a day looks
Active by day, swimming among coral and rock and usually feeding towards the lower part of the tank.21
Grooming and care the hands-on bits
Easy care. Offer several hiding places and peaceful tankmates; small groups do best in odd numbers.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 coral-rich patches of sheltered lagoons and inshore reefs at about 1 to 16 m.312
Food basics what goes in the bowl
An omnivore. Wild fish eat plankton, algae and small crustaceans. In aquariums offer spirulina, flake foods and mysis or other meaty foods.23
Company who they like around
Juveniles gather in small groups while adults live alone or in pairs. In aquariums it can be kept in small odd-numbered groups of about 3 to 7.23
The story where it all began
The American ichthyologist Henry Weed Fowler described the species in 1918. Its colours, hardiness and low price have made it a popular first fish for new marine aquarium keepers.21
Fun facts for the dinner table
- 1
A female lays around 300 eggs, which hatch within about four days while the male stands guard.2
- 2
A single male can end up caring for up to about 10,000 eggs from several females in his territory.2
- 3
Females pick a partner by checking the size of his territory and how many eggs he is already guarding.2
- 4
It can darken its colours in response to its surroundings.2
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 Yellowtail 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
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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: Chrysiptera parasema, Goldtail demoiselle fishbase.seused for distribution, size, depth, habitat, breeding, IUCN status, describer
- Wikipedia: Chrysiptera parasema en.wikipedia.orgused for colours, diet, behaviour, breeding, lifespan, aquarium notes
- LiveAquaria: Yellowtail 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.