Carpet Anemone

Stichodactyla haddoni

The "fly-paper" sand anemone — big, gorgeous, and strong enough to catch and eat fish (even a clownfish).

Difficulty: AdvancedAnemoneNot reef-safe

The carpet anemone (Stichodactyla — Haddon's S. haddoni and the giant S. gigantea) is the biggest, most dramatic host anemone in the hobby, and the most dangerous. Its short, dense tentacles work like fly-paper: anything that touches the disc sticks, and the anemone can catch and eat fish — bottom-dwellers, tangs that rest on it, even a clownfish that isn't properly bonded to it. It's a deep-sand animal for a large, mature, brightly-lit tank, and it's expert-only — with S. gigantea notoriously high-mortality.

⚠️ Safety — read first: A carpet anemone's sting is strong enough to catch and eat fish — even the clownfish you bought to host it — and it can sting a human. Never let one get pulled into a powerhead: a ruptured carpet can crash the whole tank.

Good to know: Its sticky sting can catch and eat fish — even the clown meant to host it. Expert-only; S. gigantea especially is high-mortality (choose S. haddoni). Deep sand bed required.

📊 What keepers actually ask: The recurring hard lessons are “it ate my fish” (or my clownfish) and the S. gigantea that faded away over weeks — which is exactly why experienced keepers steer newcomers to Haddon's, in a species tank, and warn against buying a giant carpet as a first anemone.

Care at a glance

Adult size	Big — commonly ~1–2 ft across, and exceptional Haddon's carpets approach 3 ft. (A mini/“maxi-mini” carpet, S. tapetum, stays 4–6 in.)
Lifespan	Not well documented — anemones can be very long-lived when healthy, but no reliable captive figure exists, so don't count on a set number.
Minimum tank	~30 gallons is the absolute floor for Haddon's; a large, mature system is strongly preferred given the adult size and the deep sand bed it needs.
Lighting	High — roughly PAR 200–300+ for Haddon's (a mini carpet takes ~150–250). Photosynthetic, so bright, stable light is essential.
Water flow	Low-to-moderate, gentle turbulent flow; cut the flow right down while it settles and acclimates.
Placement	A SAND-dweller — Haddon's buries its foot in a deep 3–5 in sand bed (the giant carpet anchors to solid material set within the sand). Place it BEFORE other livestock, and screen every pump: a wandering carpet in a powerhead can rupture and crash the tank.
Temperature	~75–82°F (24–28°C) — stability matters more than the exact set-point.
pH	8.1–8.4.
Specific gravity	1.023–1.025.
Other targets	dKH ~8–12; zero copper, as with any invert.
Feeding	Photosynthetic PLUS an aggressive meaty eater — spot-feed mysis, brine, chopped shrimp/clam/mussel or silversides cut smaller than the mouth, roughly 1–3× a week. Don't overfeed.
Temperament	Extremely powerful, sticky sting — it is a genuine predator that catches and eats fish, and it's one of the few anemones that can sting a human. A large, stressed one can discharge and harm the whole tank.
Reef-safe	No — not reliably reef-safe. Its potent sting harms corals and other anemones, and it eats fish and inverts. Treat it as a species-display animal, not a mixed-reef citizen.
Natural range	Indo-Pacific (and Red Sea).

Beginner-friendly, done right. Expert-only, and the species matters. Haddon's carpet (S. haddoni) is the more keepable one; the giant carpet (S. gigantea) is notoriously high-mortality — hard to acclimate, prone to infection in transit, and inclined to slowly “fade away” if it wasn't collected and shipped in perfect condition. Beyond the specimen, the hazards are real: a fly-paper sting that catches and eats fish (including a mismatched clownfish), a deep-sand requirement, high light, and a wanderer that must never reach a powerhead. This is not a casual reef pet.

The fish store gets these wrong

Common myths, kindly corrected — no shame for having believed them.

“Add a clownfish and it's safe.” False — a non-bonded or weak clown can be caught and eaten. Hosting is species-specific and never guaranteed.
“It's reef-safe like a coral.” No — its potent, wandering sting and fish/invert predation make it unsafe for a mixed reef.
“Gigantea and haddoni are interchangeable.” No — the giant carpet is far higher-mortality; if you must keep a carpet, start with Haddon's, never gigantea.
“It'll sit where I put it.” It buries its foot but can still wander — an unscreened powerhead is a classic, avoidable disaster.

Before you buy

Expert-level experience and, ideally, a species tank — this animal eats fish.
A deep (3–5 in) soft sand bed and a large, mature, brightly-lit system.
The right species: choose S. haddoni over the high-mortality S. gigantea.
Every powerhead and overflow screened before it goes in.
A healthy, well-coloured, firmly-attached specimen — poor imports fade away.

Signs something's wrong

A struggling invert is usually telling you about water quality, acclimation, or (for shrimp and crabs) a fresh moult — here's what to watch for:

Mouth gaping open and staying open — distress.
Bleaching or going pale — zooxanthellae loss; a badly bleached carpet often won't recover.
Slowly shrinking and “fading away” — the classic giant-carpet decline.
Won't eat, spits food, or shows mushy/disintegrating tissue — often a transit infection; and a detached, drifting foot is heading for a pump.

Never

Never keep one with small or bottom-dwelling fish you value — the sticky disc catches and eats them.
Never assume a clownfish is safe with it — a mismatched or weak clown can be eaten.
Never start with a giant carpet (S. gigantea) — it's high-mortality; choose Haddon's.
Never run unguarded powerheads — a wandering carpet that ruptures can crash the tank.
Never keep it over a shallow/bare bottom, or add it to an immature tank.

Common carpet anemone questions

Can a carpet anemone really eat a fish?

Yes. Its short, dense tentacles work like fly-paper — any fish that touches the disc sticks fast and gets consumed. Bottom-dwellers, tangs that rest on it, and even a mismatched clownfish are all at risk. This is the number-one reason it isn't a casual reef pet.

Will a carpet anemone eat the clownfish I bought to host it?

It can. Only a properly bonded, compatible clown is reasonably safe; a non-matched or weak clownfish can be caught and eaten. Never assume the pairing will just work.

Should I get a giant carpet (gigantea) or a Haddon's carpet?

Haddon's (S. haddoni). The giant carpet (S. gigantea) is notoriously high-mortality — hard to acclimate and prone to slowly fading away. Even Haddon's is expert-level, but it's far more forgiving.

Does a carpet anemone go on sand or rock?

Sand. Haddon's buries its foot in a deep 3–5 inch sand bed; the giant carpet anchors to something solid set within the sand. Give it real depth, and place it before adding other livestock.

How much light and flow does a carpet anemone need?

High light (roughly PAR 200–300+ for Haddon's) and low-to-moderate, gentle turbulent flow — turn the flow right down while it acclimates. It's photosynthetic and also an aggressive meaty eater.

Can a carpet anemone hurt me?

Yes — Haddon's is one of the few anemones whose sting can affect a human, so handle it carefully. And never let one get pulled into a powerhead: a large ruptured carpet can crash the whole tank.

Sources & further reading

This guide was written and fact-checked against these authorities. It's honest, general guidance — not a diagnosis, and not a substitute for an aquatic vet or your own test kit:

Tropical Fish Hobbyist — The Carpet Anemones — haddoni vs gigantea size/placement (sand-buried foot), photosynthetic + carnivorous feeding, fly-paper sting & fish predation, clown host lists, pH 8–8.4, warning signs, place before other livestock
Reef Chasers — Haddoni Carpet Anemone Care Guide — PAR 200–300, low-moderate flow (kill flow to acclimate), 3–5 in sand bed, temp 82°F (77–84), pH 8.0–8.4, EXPERT, "wipe out whole tank" sting warning, Indo-Pacific
LiveAquaria — Haddon's Carpet Anemone — size up to 3 ft, min tank 30 gal, SG 1.023–1.025, temp 72–78°F, dKH 8–12, pH 8.1–8.4, High light/Medium flow, Difficult, Aggressive, reef-safe with caution, clown host list
AquariumBreeder — Proper Care for Carpet Anemones — min tank 50 gal, feeding 2–4×/wk, temp 75–82°F, SG 1.023–1.025, pH 8.1–8.4, oral-disc sizes, eats non-compatible clownfish and bottom-dwelling fish

Written and fact-checked by The Coralkin Team against marine-aquarist sources — if your carpet anemone is struggling, it's almost always water quality, acclimation or a moult — check those first and ask an experienced reefer. We never guess a care number.

🔬 Review status: team-written and fact-checked against cited sources · not yet reviewed by a marine vet. How we research & fact-check →

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