Sea Anemone Types & Reef Safety Guide

Host anemones vs non-host anemones

Only ten anemone species host clownfish in the wild, according to Fautin and Allen's field guide: the bubble tip, magnificent (Ritteri), sebae (leathery), delicate, beaded, long tentacle, adhesive, and the gigantic, Haddon's and Mertens' carpet anemones. All come from the Indo-Pacific and Red Sea.

Non-host anemones are kept for their own looks. The Condy, curleycue and rock flower anemones are Caribbean species, so no Indo-Pacific clownfish has evolved with them; a clownfish that tries a Condy can be stung or eaten. The mini maxi is an Indo-Pacific carpet relative that some captive clowns use, but it is not one of the ten.

Taxonomy note: WoRMS now places the magnificent, sebae, delicate and long tentacle anemones in the genus Radianthus. This guide also shows the older Heteractis and Macrodactyla names that the field guide and most shops use.

Best anemone for clownfish

Maroon, Tomato, Cinnamon and Clarkii clownfish use bubble tips in the wild. Captive-bred Ocellaris and Percula naturally live in Ritteri and carpet anemones, which are hard to keep, but they often move into a bubble tip in aquariums. Sebae clownfish want a Haddon's carpet, which needs a large, brightly lit tank. Clownfish do not need an anemone to thrive; see the clownfish types guide for each species' hosts.

Are anemones reef safe?

Anemones are "reef safe with care". They do not eat corals, but they sting anything their tentacles touch and they move when unhappy, so a wandering anemone can burn a row of corals or end up in a pump. Keep these rules:

• Add one only to a mature tank (about 6+ months) with stable water and lighting.
• Guard every powerhead, return and overflow intake with foam or mesh.
• Leave space around it, and do not mix anemone species in small tanks.
• Carpets (Haddon's Carpet Anemone and relatives) can catch and eat fish; choose tankmates accordingly.

Can you touch a sea anemone?

Sea anemones are cnidarians, like corals and jellyfish. Their tentacles are armed with stinging cells called nematocysts that fire tiny threads into prey. Most aquarium anemones feel sticky rather than painful on fingertips, but softer skin reacts more, carpet anemones grip hard, and some people develop rashes after repeated contact.

Wear long aquarium gloves when you work near an anemone, wash your hands afterwards, keep fingers away from your eyes and mouth, and stop children touching them. Handling also stresses the anemone, so move it only when you must (gently free the foot with a fingertip rather than pulling).

How many species of sea anemone are there?

More than 1,000 species of sea anemone are known (order Actiniaria), from tiny ones half an inch across to giants about six feet wide, according to National Geographic. The World Register of Marine Species keeps the current list of accepted names. Only about ten of those species host clownfish, and the aquarium trade regularly sells only a few dozen.

Pest anemones: Aiptasia and Majano

Aiptasia (Exaiptasia diaphana) is a small, translucent brown anemone on a stalk; Majano (Anemonia manjano) is green to brown with bulb-tipped tentacles. Both arrive on live rock and frags, multiply fast and sting corals. Do not scrape or cut them in the tank; fragments regrow. See the reef hitchhiker identifier for control options.