Long-Tentacle AnemoneThe long-tentacle anemone (Macrodactyla doreensis), or “LTA,” is the sand-bed host anemone — the one that buries its foot deep in soft sand instead of anchoring in rock like a bubble-tip. Give it a mature tank, a 3–5 in soft sand bed, moderate-to-strong light and gentle indirect flow and it becomes a striking, long-lived host. The catch most keepers miss: its natural clownfish are Clark's and the pink skunk — an ocellaris or percula will often simply ignore it.
Care at a glance
| Adult size | Commonly a 4–6 in oral disc, but the full tentacle spread can reach 12–20 in — plan for the spread, not the disc. |
|---|---|
| Lifespan | Host anemones are extremely long-lived (potentially decades); a firm captive figure isn't well documented, so success is measured in years of stability, not a set number. |
| Minimum tank | ~30 gallons and up, and only a mature, established tank — plus a deep 3–5 in soft sand bed for it to anchor its foot. |
| Lighting | Moderate-to-high reef light — roughly PAR 200–300. |
| Water flow | Low-to-moderate, indirect flow — it dislikes a direct powerhead stream. |
| Placement | A SAND-dweller: it buries its pedal foot in a deep (3–5 in) soft sand bed, usually gripping buried rock beneath. Avoid crushed coral, which can cut its foot. This is the key difference from a rock-anchoring bubble-tip. |
| Temperature | ~76–82°F (24–28°C) — sources split between the low-70s and low-80s, so keep it stable within that band. |
| pH | 8.1–8.4. |
| Specific gravity | 1.023–1.025 (~35 ppt). |
| Other targets | dKH ~8–12; like all inverts, zero tolerance for copper. |
| Feeding | Photosynthetic (via zooxanthellae) PLUS small meaty foods — mysis, chopped fish, shrimp or mussel — roughly 1–3× a week. Don't overfeed. |
| Temperament | A moderate stinger — it can sting corals within reach and catch small, slow fish. Give it a buffer zone. |
| Reef-safe | With caution — it stings corals it touches and can wander; site it with space from corals and screen your pumps. |
| Natural range | Indo-Pacific / Western Pacific. |
The fish store gets these wrong
Common myths, kindly corrected — no shame for having believed them.
- “My ocellaris/percula will host it.” Often false — the LTA's natural hosts are Clark's and pink skunk clowns; ocellaris and percula frequently ignore it.
- “Any substrate is fine.” No — it needs a deep 3–5 in soft sand bed to bury its foot, and crushed coral can lacerate that foot.
- “I can add it to my new tank.” Host anemones need a mature, stable system — adding one too early is a top cause of loss.
- “It's fully reef-safe.” It stings corals within reach and can catch small fish; give it a clear buffer zone.
Before you buy
- A deep (3–5 in) soft sand bed — the non-negotiable it's most often denied.
- A mature, stable, established tank (this is a host anemone, not a beginner's first buy).
- Moderate-to-high light (~PAR 200–300) and gentle, indirect flow.
- Screen every powerhead intake and overflow — it can wander.
- Realistic expectations on hosting: Clark's and pink skunk clowns are its natural partners.
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:
- Deflated, or mouth gaping and staying open — a stressed or declining anemone; test water and be ready to remove it before it fouls the tank.
- Constant wandering that never settles — usually light, flow or unstable water; a roaming anemone is also at risk in pumps.
- Shrinking, fading or turning pale/translucent (bleaching) — a light, feeding or stability problem.
- Detaching and tumbling in the flow — check it hasn't drifted toward a powerhead, and stabilise conditions.
Never
- Never add it to a new or unstable tank — the top killer of host anemones.
- Never keep it over crushed coral or a shallow/bare bottom — it needs deep soft sand for its foot.
- Never run unguarded powerhead intakes or overflows — a wandering anemone gets shredded.
- Never dose copper-based medications with any anemone in the tank.
- Never buy one assuming an ocellaris or percula will host it.
Common long-tentacle anemone questions
Does a long-tentacle anemone need sand or rock?
Sand — a deep, soft bed of about 3–5 inches to bury its foot in (it often grips buried rock underneath). This is the big difference from a bubble-tip, which anchors its foot in rock. Crushed coral is a poor choice because it can cut the foot.
Will my ocellaris clownfish host a long-tentacle anemone?
Maybe, but don't count on it. The LTA's natural hosts are the Clark's clownfish and the pink skunk clownfish; ocellaris and percula often ignore it. An individual clown may or may not adopt one, and no clownfish needs an anemone to be healthy.
How big a tank does an LTA need?
Around 30 gallons or more, and it must be a mature, stable, established tank — plus a deep soft sand bed. Anemone stability matters far more than a big tank number.
How much light and flow does it want?
Moderate-to-high reef light (roughly PAR 200–300) and low-to-moderate, indirect flow. It dislikes a direct powerhead stream, so aim the flow across it, not at it.
Do I have to feed a long-tentacle anemone?
It gets energy from light via its symbiotic zooxanthellae, but it does best with small meaty foods — mysis, chopped fish, shrimp or mussel — about 1–3 times a week. Don't overfeed.
Is a long-tentacle anemone reef-safe?
Only with caution. It stings corals within reach and can catch small, slow fish, and it can wander until it settles. Give it a buffer from corals and screen your pumps.
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:
- Reef Chasers — Long Tentacle Anemone Care Guide — PAR 200–300, 3–5" sand bed, low-moderate flow, moderate difficulty, temperature band, pH, Indo-Pacific
- AquariumDomain — Long Tentacle Anemone Species Profile — 30-gal min, semi-aggressive, temp 72–79°F, pH 8.1–8.4, SG 1.023–1.025, sand-burying placement, carnivore feeding, clown hosts
- LiveAquaria — Long Tentacle Anemone — 30-gal min, moderate care, dKH 8–12, ~4" sand/rubble substrate, hosts A. perideraion & A. clarkii
- TFH Magazine — Host Anemones and Clownfishes — natural hosts limited to Clark's and pink skunk; grows well over a foot across
Written and fact-checked by The Coralkin Team against marine-aquarist sources — if your long-tentacle 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 →