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Phylum Chordata > Subphylum Vertebrata > fishes > Family Pomacentridae
Amphiprion sp.
Family Pomacentridae
updated Sep 2020

if you learn only 3 things about them ...
Anemonefish need their anemones. Do not disturb them or their anemones.
One anemone may be home to many anemonefishes.
These fishes are threatened by over-collection for the aquarium trade. Don't keep Nemo in your home, he belongs in the ocean.

Where seen? Made famous by the cartoon "Finding Nemo", these fishes are a delight and the highlight of a trip. Anemonefishes are commonly seen among the sea anemones of our Southern shores. At low tide, they may shelter in a pool nearby while their anemone is left high and dry.

What are anemonefishes? Anemonefishes belong to the Family Pomacentridae. Anemonefishes are in the subgroup Amphiprioninae in this family.

To about 9cm. An eye-catching red-and-white pattern, rounded fins, and 'wriggling' deep among a sea anemone's tentacles
makes this fish quite unmistakable. Indeed, the most amazing feature of anemonefishes is that they can live happily among the tentacles of sea anemones that would otherwise kill (and eat) other fishes, including larger fishes.

Home Sweet Anemone Home: On our intertidal, the Clown anemonefish is often seen in Giant carpet anemones. It is also sometimes in Magnificent anemones and Merten's carpet anemones. While the Tomato anemonefish is mainly found in Bubble-tip anemones.

Experiments suggest anemonefishes may protect their host anemones from predatory fishes such as butterflyfish. They may also clean the anemone of parasites and remove dead tissues of the sea anemone. Their swimming action may also increase water circulation around the sea anemone and remove sediments that would foul the sea anemone. Some studies suggest anemonefishes attract other fishes that are captured and eaten by the sea anemone.

In return, the anemonefishes enjoy protection among the tentacles of the sea anemone and may also feed on leftovers of prey captured by the host sea anemone. In captivity, the anemonefish and anemone can survive well without each other. However, in the wild, the anemonefish being poor swimmers, are soon eaten by larger fishes. The anemonefish also needs the protection of a sea anemone to lay its eggs, usually under the oral disk of the anemone.

The anemonefish may sometimes be seen stranded at low tide near its anemone home. It is probably best to leave it alone and NOT try to 'rescue' it by putting it in a pool of water far away from its anemone home. These fishes are adapted to surviving at low tide and it is best that they are are close as possible to their anemone home when the tide turns. As the water rushes in, so do predators which will quickly eat up a defenceless anemonefish far from its protective anemone.

In a Magnificent anemone.
Terumbu Semakau, Jul 14

In a Merten's carpet anemone.
Terumbu Hantu, Apr 12

Stranded at low tide: best to leave it alone.
Kusu Island, Aug 19
How do they stay alive in a sea anemone? The anemonefish is believed to develop this immunity slowly. To acclimatise to a host anemone, an anemonefish will at first gingerly swim among the tentacles, touching it with its fins then withdrawing rapidly, in an elaborate dance. Only after some time will the fish be able to dive right in among the tentacles. One theory is that the fish smears mucus from the anemone all over itself. In this way, to the anemone, the fish is just another part of the anemone. Thus the sea anemone doesn't sting the fish. Another theory is that the mucus of the fish (all fishes are covered in mucus) lacks substances that trigger a sea anemone to discharge its stingers.

What do they eat? Anemonefishes eat mainly plankton. Some also graze algae from the surface or gathered from the water.

Fishes of several different sizes in one anemone.
Pulau Pawai, Dec 09
Photo shared by Loh Kok Sheng on flickr.

Eggs laid near the host sea anemone.
Terumbu Raya, Jun 15

Photo shared by Toh Chay Hoon on facebook.
Amazing gender switch: Anemonefishes can change their gender. Often, a sea anemone will be home to several anemonefishes of the same species. Usually the largest anemonefish in the group is the female and the next largest is the functioning male (although he is often less than half her size). If the female is removed from the group, the male becomes a female and the next largest becomes the dominant male. In this way, anemonefishes can continue to breed throughout the year. Small anemonefishes are not necessarily younger, just lower in the "pecking order". It is believed they remain small because of the constant harassment by the dominant pair. Small anemonefishes are thus NOT the babies of larger anemonefishes in the same anemone.

Anemonefish babies: Anemonefishes form permanent pair bonds that sometimes last for years. The male usually selects the nest site, often a bare rock near the sea anemone which he clears of seaweeds and other rubbish. The female eventually helps out. After the female lays on the site, the male scrupulously guards and cares for the eggs, keeping them well aerated and clean. The female helps out sometimes. Larval fish that hatch from the eggs drift with plankton for 8-12 days before settling to the bottom and changing into a juvenile fish.

How does the baby fish find an anemone host? Each species of anemonefish lives in a specific species of sea anemone. Some species apparently follow chemicals released by the suitable host anemone, others find one by sight, for yet others, it is apparently simply by chance. One study suggests the fishes use the smell of leaves from the rainforest to find their way to a suitable habitat. Even so, this is not the end of the problems for the young fish. If the anemone already has resident anemonefishes, the new fish is usually bullied by the residents and may even be driven away.
Pulau Semakau, Apr 17
Tomato anemone fish (Amphiprion frenatus) in Bubble-tip anemone (Entacmea quadricolor)
Human uses: Unfortunately, these fishes are taken in large numbers from the wild for the aquarium trade. The harvest may involve the use of cyanide or blasting, which damage the habitat and kill many other creatures. Like other fish and creatures harvested from the wild, most die before they can reach the retailers. Without professional care, most die soon after they are sold. Often of starvation as owners are unable to provide the small creatures and plants that these fishes need to survive. In artificial conditions, many succumb to diseases and poor health. Those that do survive are unlikely to breed.

There have been some success in breeding anemonefish for the aquarium trade. Although captive bred anemonefish are hardier, they are more expensive. Harvesting from the wild will probably continue so long as there are unscrupulous traders and aquarists.
Thus, anemonefishes continue to be unsustainably harvested from the wild. The pressure on wild populations has risen tremendously due to the huge demand following the popular "Finding Nemo" cartoon.

Status and threats: All our anemonefishes are 'Vulnerable' in the Red List of threatened animals of Singapore. Like other creatures of the intertidal zone, they are affected by human activities such as reclamation and pollution. Poaching by hobbyists and overfishing can also have an impact on local populations. According to the Singapore Red Data Book, "habitat protection and strict policing against illegal collection are required" to conserve our anemonefishes.

Some Anemonefishes on Singapore shores

Amphiprion species recorded for Singapore
from Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore.
*additions from from Ng, P. K. L. & Y. C. Wee, 1994. The Singapore Red Data Book: Threatened Plants and Animals of Singapore.
in red are those listed among the threatened animals of Singapore
from Davison, G.W. H. and P. K. L. Ng and Ho Hua Chew, 2008. The Singapore Red Data Book: Threatened plants and animals of Singapore.
**from WORMS
+Other additions (Singapore Biodiversity Records, etc)

  Family Pomacentridae
  Amphiprion clarkii (Clark's anemonefish) (VU: Vulnerable)
Amphiprion frenatus (Tomato anemonefish) (VU: Vulnerable)
Amphiprion ocellaris
(False clown anemonefish) (VU: Vulnerable)
Amphiprion polymnus
(Saddleback anemonefish) (VU: Vulnerable)
Amphiprion perideraion
(Pink skunk anemonefish) (VU: Vulnerable)

  • Toh Chay Hoon. 11 April 2014. Spawn of the saddleback anemonefish. Singapore Biodiversity Records 2014: 96.
  • Jeffrey K. Y. Low. 2013. More noteworthy fishes observed in the Singapore Straits. Nature in Singapore, 6: 31–37.
  • Toh Chay Hoon. 20 December 2013. Shrimps and saddleback anemonefish on carpet anemone off Pulau Hantu: Holthuis’s anemone shrimp, Periclimenes holthuisi and Saddleback anemonefish, Amphiprion polymnus. Singapore Biodiversity Records 2013: 126-127.
  • Chou, L. M., 1998. A Guide to the Coral Reef Life of Singapore. Singapore Science Centre. 128 pages.
  • Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore. National Council on the Environment. 163pp.
  • Davison, G.W. H. and P. K. L. Ng and Ho Hua Chew, 2008. The Singapore Red Data Book: Threatened plants and animals of Singapore. Nature Society (Singapore). 285 pp.
  • Allen, Gerry, 2000. Marine Fishes of South-East Asia: A Field Guide for Anglers and Divers. Periplus Editions. 292 pp.
  • Kuiter, Rudie H. 2002. Guide to Sea Fishes of Australia: A Comprehensive Reference for Divers & Fishermen New Holland Publishers. 434pp.
  • Lieske, Ewald and Robert Myers. 2001. Coral Reef Fishes of the World Periplus Editions. 400pp.
  • Lim, S., P. Ng, L. Tan, & W. Y. Chin, 1994. Rhythm of the Sea: The Life and Times of Labrador Beach. Division of Biology, School of Science, Nanyang Technological University & Department of Zoology, the National University of Singapore. 160 pp.
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