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Phylum Cnidaria > Class Anthozoa > Subclass Zoantharia/Hexacorallia > Order Actiniaria
Magnificent anemone
Heteractis magnifica
Family Stichodactylidae
updated Nov 2019
if you learn only 3 things about them ...
They are found among the coral rubble. Don't step on them!
Don't remove any fishes or shrimps that live in the anemone. They will die and the anemone will also suffer.
Don't poke the anemone to try to make fishes or shrimps come out. They will instead hide deeper in the anemone.

Where seen? This stunning, large anemone is well named. It is seen on our Southern shores, attached to large boulders of dead coral or other solid objects. It is rarely buried in sand or sediments. Several of these anemones may be found next to one another. The anemone was previously known as Radianthus ritteri.

Features: Diameter when expanded 30-50cm, but can reach 1m. Body column uniformly coloured. Those seen were white, pink, maroon, purple. The body column has longitudinal rows of translucent verrucae of the same colour or slightly lighter or darker than the body column.

Long tentacles (5-8cm) densely cover the oral disk. The tentacles are finger-like and do not taper. The tips are blunt or slightly swollen. The lower part of the tentacles are usually the same colour as the oral disk. Tips may be yellow, green or white. It is said that the mouth area of 2-3cm in the centre of the oral disk is usually yellow, brown or green and the
mouth is often raised so it sits on a cone. But this has not been observed for those seen at low tide. The animal can tuck all its tentacles into its body column, forming a ball-shape with only tufts of tentacles sticking out in the centre.

Sometimes confused with other large sea anemones and similar large cnidarians. Here's more on how to tell apart large sea anemones with long tentacles and large 'hairy' cnidarians.

The animal can tuck its tentacles
into its body.
Kusu Island, May 04

Long tentacles densely cover the oral disk.

Sea anemone in the process of cloning itself!
Pulau Hantu, Jul 20
Photo shared by Dayna Cheah on facebook.

Pulau Hantu, Jan 10

Pulau Hantu, Feb 08

Terumbu Pempang Tengah, Apr 12
Magnificent friends: The Magnificent anemone harbours symbiotic algae (called zooxanthellae) that photosynthesize. The algae share the food produced with the anemone, which in turn provides the algae with shelter and minerals.

Several kinds of animals may live happily among and unharmed by the tentacles of the Magnificent anemone. These include A
nemone shrimps like the Peacock-anemone anemone shrimp (Periclimenes brevicarpalis) and fishes such as Dascyllus trimaculatus and anemonefishes including A. akallopisos, A. bicinctus, A. clarkii, A. nigripes, A. ocellaris (Clown anemonefish), A. percula, A. perideraion, A. xanthurus.

Status and threats: Magnificent anemones are not listed among the endangered animals of Singapore. However, like other creatures of the intertidal zone, they are affected by human activities such as reclamation and pollution. Trampling by careless visitors, and over-collection also have an impact on local populations.

A small fish caught in its tentacles.
Kusu Island, Dec 18
Photo shared by Loh Kok Sheng on facebook.

Peacock-tail anemone shrimp on the anemone.
Pulau Hantu, Apr 04

Clown anemonefish lives safely in the anemone.
Pulau Semakau, Aug 11

Magnificent anemones on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores

St. John's Island , Apr 12
Photo shared by Loh Kok Sheng on his blog.

Pulau Jong, Jun 12
Photo shared by Loh Kok Sheng on his blog.

Terumbu Bemban, Jul 11
Photo shared by James Koh on his blog.

Terumbu Bemban, 24
Photo shared by Kelvin Yong on facebook.

Terumbu Raya, Jun 20
Photo shared by Jianlin Liu on facebook.

Terumbu Pempang Darat, Jun 10
Photo shared by James Koh on his blog.

Pulau Senang, Jun 10

Photo shared by Loh Kok Sheng on his flickr.

Pulau Senang, Jun 10

Photo shared by Loh Kok Sheng on his flickr.

Pulau Pawai, Dec 09

Photo shared by James Koh on his flickr.

Pulau Salu, Apr 21
Photo shared by Loh Kok Sheng on facebook.

Pulau Berkas, Feb 22
Photo shared by Loh Kok Sheng on facebook.

  • Daphne Gail Fautin, S. H. Tan and Ria Tan. Dec 2009. Sea anemones (Cnidaria: Actiniaria) of Singapore: abundant and well-known shallow-water species. The Raffles Bulletin of Zoology. Pp. 121-143.
  • Erhardt, Harry and Daniel Knop. 2005. Corals: Indo-Pacific Field Guide IKAN-Unterwasserachiv, Frankfurt. 305 pp.
  • Gosliner, Terrence M., David W. Behrens and Gary C. Williams. 1996. Coral Reef Animals of the Indo-Pacific: Animal life from Africa to Hawaii exclusive of the vertebrates Sea Challengers. 314pp.
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