TankBud

Magnificent anemone

Heteractis magnifica

Also known as Ritteri Anemone, Magnificent Sea Anemone

SaltwaterAnemone

Magnificent anemone (Heteractis magnifica)
Nhobgood Nick Hobgood · CC BY-SA 3.0

Care at a glance

Temperature
75–81°F
24–27°C
pH
8.1–8.4
Adult size
19.7 in
50 cm
Minimum tank
53 gal
200 L
Temperament
Peaceful
Social behavior
Solitary
Swim level
Bottom
Difficulty
Difficult
Breeding
No record
Rarity
Rare
Reef safe
Reef safe with caution
Family
Stichodactylidae
Origin
Indo-Pacific reefs (East Africa and the Red Sea to Polynesia)

Overview

Needs very strong lighting and vigorous, turbulent flow, along with target feedings of meaty foods two or three times a week. It roams more than almost any other host anemone, drifting across the tank in search of better light and current even after it seems settled, so every powerhead and overflow needs a guard and every coral needs real breathing room from wherever it might end up. Ocellaris, clark's, and pink skunk clownfish are its classic hosts, along with several other Amphiprion species across its range. This is an expert level animal: it should only go into a large, mature reef tank with reef-grade lighting and flow already dialed in, and it needs a slow drip acclimation and time to settle before it is judged a success or failure.

In the wild

Ranges across the Indo-Pacific from East Africa and the Red Sea to Polynesia, usually attached to hard substrate in shallow, well lit, high flow water on the reef crest or upper slope. It is widely considered the premier clownfish host anemone for its size and color, but it is also one of the most demanding: it wants intense light and strong, turbulent flow that closely mimics a shallow reef crest, conditions many home tanks cannot fully deliver.

Good to know

Currently accepted by the World Register of Marine Species as Radianthus magnifica, though Heteractis magnifica remains the name most hobbyists know it by. Its oral disc typically spans 20–50 cm but can reach a meter in exceptional wild specimens, with a retracted column that ranges from electric blue or green to red, pink, or purple. It hosts symbiotic zooxanthellae as its main energy source and can live for decades: one well documented aquarium specimen reportedly reached about 80 years old.

Did you know

A single magnificent anemone can host an entire clownfish family at once: a dominant breeding pair plus a string of smaller, non-breeding juveniles queued up by size, all sharing one anemone until the largest fish dies or is removed and the next in line steps up to become the new breeding female.

Symbiotic relationships

Clownfish and their host anemones

A clownfish lives inside an anemone that stings and eats other fish its size. Its mucus coat keeps the anemone's stinging cells from firing, and a new fish builds that protection up over hours of brief touches. The fish gets a refuge no predator will follow it into and a nest site at the anemone's base. The anemone gets a guard that drives off the butterflyfish that would graze its tentacles, a steady supply of nitrogen from the fish's waste, and water movement at night, when the fish fans its fins among the tentacles and the anemone takes up more oxygen. Only ten anemone species host clownfish in the wild, and each clownfish species uses its own short list of them.

Captive-bred clownfish have never seen an anemone and do not need one; they settle for a coral, a powerhead or a corner of the tank. If you want the pairing, the anemone is the harder animal by far and goes in first, into a mature tank with strong light and stable water, at the tank size its own profile lists. The bubble tip anemone is the hardy host, and the one most clownfish accept in captivity even when it is not a natural host, so a clownfish profile lists it as the usual tank host where that is the case. The sebae, magnificent and carpet anemones are marked difficult, and the carpets eat fish. Expect a paired clownfish to defend its anemone against everything else in the tank.

Shrimp and crabs that live in anemones

Several small crustaceans live where almost nothing else can: among the tentacles of an anemone. Sexy shrimp perch in the tentacles in a cluster, bobbing their tails in the display that named them. The white-spot anemone shrimp is near transparent apart from its spots and lives on carpet anemones. The porcelain anemone crab sits at the anemone's edge and filters plankton from the water with two fan-like arms. Pederson's cleaner shrimp lives in the Caribbean corkscrew anemone and cleans fish from there. In every case the anemone is a bodyguard: its sting keeps off the small fish that would eat the shrimp. The anemone gains little, and the white-spot shrimp will nibble its host's tentacles when it is hungry.

Give each of them its anemone. Sexy shrimp take a rock flower anemone, a bubble tip or a carpet. The white-spot shrimp and the porcelain crab want a carpet anemone or a long tentacle anemone, both of which need a mature tank at the tank size their profiles list. Pederson's shrimp wants a corkscrew anemone or a condy. Without a host they perch on a coral or hide in the rock and are picked off by any fish that eats shrimp, so they suit a peaceful nano reef. A clownfish will evict them from an anemone it has claimed.

Every symbiotic relationship in the catalog

Common questions

What size tank does a Magnificent anemone need?

A Magnificent anemone needs at least 53 gal (200 L). It spends most of its time in the bottom.

What temperature and pH does a Magnificent anemone need?

A Magnificent anemone is comfortable at 75–81°F (24–27°C) with a pH of 8.1–8.4.

How big does a Magnificent anemone get?

An adult Magnificent anemone reaches about 19.7 in (50 cm).

Related species