Reef aquarium anemones

An anemone is a coral that walks. Every anemone but the tube anemone needs the light a stony coral needs, because it feeds on its own algae. It needs meaty food about once to a few times a week on top, and some carpets take more. It needs a tank that has been stable for six months, because it will not forgive the swings of a new one. It needs the powerhead intakes guarded, because an anemone that wanders in the night ends up shredded in a pump. And it needs room, because everything it touches gets stung, and a moving anemone kills corals on its way past. The tube anemone has no algae, so it lives on small foods like mysis fed at least twice a week.

1. 01

   Strong light

   All but the tube anemone feed on their algae and starve in the dark

2. 02

   A mature tank

   Six months of stable water before it goes in

3. 03

   Guarded intakes

   A wandering anemone dies in a powerhead

4. 04

   Room to sting

   It kills any coral it settles against

Each host anemone profile lists the clownfish that use it in the wild, and the match matters more for the anemone than the fish. The long tentacle anemone reaches 15.7 inches (40 cm), lists 40 gallons (150 liters) and is the natural host of Clark's and pink skunk clownfish. The sebae anemone is the same size and marked difficult. The magnificent anemone reaches 19.7 inches (50 cm) in 53 gallons (200 liters) and is the wild home of the ocellaris and percula, and it is marked difficult because it rarely settles. The gigantea and Haddon's carpet anemones are marked difficult too. Mertens' carpet anemone and the sebae anemone host more clownfish species than either. The malu anemone is the compact host at 7.9 inches (20 cm), marked medium.

Mertens' carpet anemone reaches 35.4 inches (90 cm), lists 53 gallons (200 liters) and is marked difficult and aggressive: a carpet this size catches and eats fish, tangs and wrasses included. The tube anemone is the one marked not reef safe, 7.9 inches (20 cm) of stinging tentacles that reach any coral within range, and it buries its tube in deep sand. The condy anemone is the cheap one in the shops, and it moves and stings as much as any. It is not a natural clownfish host, and a clownfish may move in, ignore it or get stung and killed. The tube, rock flower and maxi-mini carpet anemones do not host clownfish either. The curlyque anemone is in the Aiptasia family and spreads. The aurora anemone is marked difficult for the usual reason: it walks until it finds a place it likes, or dies trying.