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    Regal blue tang

    Paracanthurus hepatus

    Also sold as Blue tang, Hippo tang, Palette surgeonfish

    Not for beginners

    Regal blue tang (Paracanthurus hepatus), photographed in the sea or an aquarium
    Photo: DerHans04, CC BY-SA 3.0, via Wikimedia Commons
    Care level
    Advanced
    Adult size
    30.5 cm in aquariums
    Minimum tank
    681 litres
    Temperament
    Semi-aggressive
    With corals
    Reef safe
    Captive-bred
    Wild-caught (captive-bred rare)
    IUCN status
    Least Concern
    Show volumes in

    How do you care for the regal blue tang?

    Semi-aggressive.

    Feeding

    Herbivore/planktivore.

    Seaweed plus meaty foods.

    Tank and special needs

    Plan for at least 681 litres of water (the care sheet says 180 US gallons).

    Very large tank; bought small after a popular film and outgrows tanks.

    Corals and invertebrates

    None.

    Which tankmates suit the regal blue tang?

    One per tank unless very large.

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

    More than one regal blue tang

    Keep one regal blue tang: 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 (4)

    • Yellow tangBoth are tangs of similar shape, which is a common trigger for fights.
    • Kole tangBoth are tangs of similar shape, which is a common trigger for fights.
    • Scopas tangBoth are tangs of similar shape, which is a common trigger for fights.
    • Powder blue tangBoth are tangs of similar shape, which is a common trigger for fights.
    Usually fine together (55)

    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.

    No known problems with the corals and anemones in this guide.

    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

    Very prone to ich, also lateral line erosion and fin erosion (LiveAquaria).

    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?

    Wild-caught in practice. Captive breeding has been reported by university researchers (about 2016) but commercial supply was not confirmed this session (not verified).

    Wild-caught; popularity spikes after films raised demand concerns (National Geographic 2016). typical, check

    Where sources disagree

    Other minimum tank sizes we found:

    • LiveAquaria adds a tank at least 6 ft (183 cm) long.

    What does it cost in the UK?

    £45 to £80. 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, disease.
    2. National Geographic articleRead 21 October 2026, search summary only. Used for: demand, cyanide.
    3. FishBase species summaryRead 21 October 2026, search summary only. Used for: max length.
    4. Kraken Corals (UK retailer) catalogueRead 21 October 2026, read in full. Used for: UK price.

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    Yellow tang

    Zebrasoma flavescens

    Care
    Intermediate
    Adult size
    20 cm
    Tank from
    378 litres
    Temperament
    Semi-aggressive
    Corals
    Reef safe

    Photo Luc Viatour, CC BY-SA 3.0

    Kole tang

    Ctenochaetus strigosus

    Care
    Intermediate
    Adult size
    18 cm
    Tank from
    265 litres
    Temperament
    Semi-aggressive
    Corals
    Reef safe

    Photo KimonBerlin, CC BY-SA 2.0

    Scopas tang

    Zebrasoma scopas

    Care
    Intermediate
    Adult size
    31 cm
    Tank from
    492 litres
    Temperament
    Semi-aggressive
    Corals
    Reef safe

    Photo William Warby, CC BY 2.0

    Powder blue tang

    Acanthurus leucosternon

    Not for beginners

    Care
    Advanced
    Adult size
    23 cm
    Tank from
    473 litres
    Temperament
    Aggressive
    Corals
    Reef safe

    Photo Diego Delso, CC BY-SA 4.0