How to Check New Corals for Pests

A new coral often looks different just after unpacking than it does later in the aquarium. Retracted polyps after transport are not proof of pests. Even so, a careful inspection is worthwhile before the coral goes into its final position. With Euphyllia in particular, we look beneath the tissue and where it meets the skeleton.

Before placing the coral: five minutes for a careful inspection

Prepare a clean container and a bright lamp. Photograph the coral and its frag plug under reasonably neutral light. Strong blue lighting can hide small animals and tissue changes among the colours. Turn the frag carefully by its plug or a suitable part of the skeleton without pressing on living tissue.

Look for movement, missing tissue, deposits or small egg clusters around the base. A short video may later help distinguish a moving organism from a fixed piece of tissue.

Flatworms: appearance alone is not a diagnosis

Flatworms may live on corals, but not every visible flatworm is the same organism, and a closed Euphyllia does not prove an infestation. Record where it sits, whether it moves and what the tissue beneath it looks like. A sharp photograph and changes over hours or days are more useful than a diagnosis based only on its outline.

Scientific studies have examined coral-dwelling Waminoa flatworms. On the Galaxea corals studied, they could interfere with feeding. This shows that such animals are not always harmless. It does not establish that every flatworm affects every Euphyllia in the same way. Identification and the condition of the particular coral matter.

If you find something suspicious

1. Document it: Take a sharp photograph under white light, ideally with a size reference. Note which coral it was on and where it was sitting.
2. Observe separately: An established quarantine tank makes continued observation easier. A bucket filled for a short time is not permanent quarantine.
3. Choose treatment for the situation: Depending on the product and organism, a coral dip may help, but it does not replace identification or follow-up checks. Follow the manufacturer's directions and confirm that the product suits the coral.
4. Keep checking: Even if nothing is visible after a dip, continue observing the coral and its frag plug. One treatment is no guarantee that everything has been removed.

Do not pour dip or shipping water into the display tank. Do not treat the entire aquarium on suspicion before you know what you have found.

Not every problem is caused by a pest

With Torch corals, a direct pump jet can stress the tissue. Too little water movement is also unsuitable. Fluctuating KH, shipping stress and other causes may contribute. Alongside possible pests, we therefore check flow and placement and recent water readings.

Imported corals can carry unwanted organisms or infections, but origin alone does not establish an infestation. Inspect every new arrival, whether imported or aquacultured. Our acclimation guide explains what to do after delivery.

When to act quickly

Visible tissue recession, tissue coming loose or rapid deterioration needs immediate attention. Do not wait several days for a definite flatworm identification. If possible, keep the coral separate, document its condition and seek specialist advice. Repeated dips and switching between treatments without a plan can further weaken an already stressed coral.

If you notice anything unusual on a CoralPrime coral, email us your order number, photographs under white light, a short video and current salinity, temperature and KH readings at info@coralprime.de. This helps us give more specific advice.

Frequently asked questions

Must every new coral be dipped immediately?

There is no universal rule. The species, condition after shipping, suitable product and available quarantine facilities determine the best approach.

My Euphyllia will not open. Is it flatworms?

You cannot conclude that from a closed polyp alone. Check the tissue and skeleton, placement and current water readings. A photo under neutral light is the best start.

Is one dip enough?

Do not rely on it. Continue observing the coral afterwards and inspect the frag plug too.