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    Chromis and damsels

    Blue damsel

    Chrysiptera cyanea

    Also sold as Sapphire devil, Royal blue damsel

    Blue damsel (Chrysiptera cyanea), photographed in the sea or an aquarium
    Photo: Brian Gratwicke, CC BY 2.0, via Wikimedia Commons
    Care level
    Beginner
    Adult size
    7.6 cm in aquariums
    Minimum tank
    114 litres
    Temperament
    Semi-aggressive
    With corals
    Reef safe
    Captive-bred
    Occasionally captive-bred
    IUCN status
    Least Concern
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    How do you care for the blue damsel?

    Semi-aggressive; territorial as it matures.

    Feeding

    Omnivore.

    Takes anything.

    Tank and special needs

    Plan for at least 114 litres of water (the care sheet says 30 US gallons).

    Rockwork.

    Why this care level

    Hardy but often regretted later because of aggression.

    Corals and invertebrates

    None.

    Which tankmates suit the blue damsel?

    Add last; hard to remove from rockwork once established.

    Suggested order in a mixed tank: add last, after the peaceful fish have settled.

    More than one blue damsel

    Keep one blue damsel: two of the same species usually fight.

    Other fish

    Checked against the other 59 fish in this guide, assuming a tank big enough for both. Individual fish differ, so treat this as a starting point.

    Avoid together (3)

    • Yellowtail blue damselBoth are Chrysiptera; close relatives defend the same space and food.
    • Azure damselBoth are Chrysiptera; close relatives defend the same space and food.
    • Humbug damselBoth are damsels of similar shape, which is a common trigger for fights.
    Usually fine together (56)

    Invertebrates

    Only the invertebrates with a known risk are listed.

    Take care (2)

    • Tiger tail sea cucumberA stressed or dead tiger tail sea cucumber can release toxins that harm fish; cover pump intakes.
    • Sea appleA stressed or dead sea apple can release toxins that harm fish; cover pump intakes.

    Corals and anemones

    Only the corals and anemones with a known risk are listed.

    Take care (1)

    These checks follow the reasons fish and invertebrates clash: same species or genus, similar shape, mouth size, temperament, food, burrows, tank size and the order they are added. Individual animals differ; every source agrees on that.

    Quarantine and health

    Hardy.

    New fish are the most common way disease gets into a reef tank. Quarantine every fish in a separate tank before it joins the display, and choose a method that suits its tolerance of copper.

    Captive-bred or wild?

    Some captive-bred.

    What does it cost in the UK?

    about £11. This is one UK retailer’s listing on 21 October 2026, not a market average, and every item was sold out on that day.

    Sources

    1. LiveAquaria (US retailer) care sheetRead 21 October 2026, read in full. Used for: stats.
    2. FishBase species summaryRead 21 October 2026, read in full. Used for: max length, IUCN.
    3. Kraken Corals (UK retailer) catalogueRead 21 October 2026, read in full. Used for: UK price.

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    Green chromis

    Chromis viridis

    Good first fish

    Care
    Beginner
    Adult size
    10 cm
    Tank from
    114 litres
    Temperament
    Peaceful
    Corals
    Reef safe

    Photo Debra Baker, CC BY 4.0

    Yellowtail blue damsel

    Chrysiptera parasema

    Good first fish

    Care
    Beginner
    Adult size
    7 cm
    Tank from
    114 litres
    Temperament
    Mostly peaceful
    Corals
    Reef safe

    Photo Brian Ong, CC BY-SA 3.0

    Azure damsel

    Chrysiptera hemicyanea

    Care
    Beginner
    Adult size
    7 cm
    Tank from
    114 litres
    Temperament
    Semi-aggressive
    Corals
    Reef safe

    Photo Haplochromis, Public domain

    Humbug damsel

    Dascyllus aruanus

    Not for beginners

    Care
    Beginner
    Adult size
    10 cm
    Tank from
    114 litres
    Temperament
    Aggressive
    Corals
    Reef safe

    Photo Rickard Zerpe, CC BY 2.0