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    Sand sifting starfish

    Astropecten polyacanthus

    Avoid in most reef tanks

    Sand sifting starfish (Astropecten polyacanthus)
    Photo: Nick Hobgood, CC BY-SA 3.0, via Wikimedia Commons
    Group
    Starfish
    Care level
    Advanced
    With corals
    Reef safe with caution

    What does the sand sifting starfish do in a reef tank?

    Sand-bed microfauna: worms, small snails, tiny brittle stars typical, check

    With corals: Yes to corals, bad for sand-bed life

    How many should you keep?

    One at most, and only in large tanks with deep, productive sand; one source doubts long-term survival even then typical, check

    One US gallon is 3.785 litres and one UK gallon is 4.546 litres, so a "per gallon" rule depends on whose gallon it means.

    What can go wrong?

    Strips the sand bed then starves, often unseen typical, check

    Which tankmates are risky?

    Fish

    Fish that may eat or harass it.

    None of the fish in this guide is known to eat or harass it.

    Other invertebrates

    Invertebrates it may harm, or that may harm it.

    Avoid together (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.

    Sources

    1. Reef Builders sand sifting starfish, 2014Read 21 October 2026, search summary only.

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    Asterina starfish

    Aquilonastra and related small asterinids

    Care
    Beginner
    Group
    Starfish
    Corals
    Reef safe with caution

    Photo Nicole Gravier-Bonnet, CC BY-SA 3.0

    Blue Linckia starfish

    Linckia laevigata

    Care
    Advanced
    Group
    Starfish
    Corals
    Reef safe

    Photo dr.scott.mills, CC BY-SA 2.0