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Phylum Cnidaria > Class Anthozoa > Subclass Zoantharia/Hexacorallia > Order Actiniaria
Snaky anemone
Macrodactyla doreensis
Family Actiniidae
updated Apr 2018

Where seen? This large anemone with snaky tentacles is sometimes seen on some of our shores, on coral rubble and near seagrasses and reefs. Although generally only exposed at the lowest tides, it is said that the anemone is generally found no deeper than 5m.

Features: Diameter with tentacles extended said to reach up to 50cm but those seen usually smaller about 20-30cm. Tentacles snaky, thick and long (about 10cm). Sometimes (not always), the tentacles may be tightly coiled or curled especially when the sea anemone is submerged. It is also called the Corkscrew Tentacle sea anemone for this reason. To some (hungry) visitors, the anemone reminds them of a bowl of udon noodles!

The tentacles are close to one another at the circumference of the oral disk, and more sparsely distributed on the oral disk. Sometimes, a broad expanse in the centre of the oral disk around the mouth has no tentacles. There are white stripes radiating from the central mouth. The stripes may extend onto the tentacles. Tentacles and oral disk usually the same colour. Tentacles may be brown, green or purplish, but tips may be darker or lighter. The oral disk is purplish-gray to brown, sometimes with a greenish cast. The underside of the oral disk is purplish with white eye-shaped non-adhesive verrucae that extend onto the white body column.

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.

Snaky friends:
The 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 have been associated with snaky anemones including anemone shrimps (Periclimenes sp.) and anemonefishes (Amphiprion sp.) including A. biaculeatus, A. clarkii (juvenile and adult), A. percula, A. perideraion, A. polymnus (juvenile and adult). But these are rarely observed on the Snaky anemones seen on the intertidal during low tide.

Human uses: Unfortunately, these beautiful animals are harvested from the wild for the live aquarium trade, although they are difficult to maintain in captivity.

Purple sea cucumbers at
the base of the anemone.
Beting Bronok, Aug 05

White stripes radiating from the centre.

White eyed-shaped verrucae.
Status and threats: This anemone is not listed among the threatened animals of Singapore. However, like other animals harvested for the live aquarium trade, most die before they can reach the retailers. Without professional care, most die soon after they are sold. Those that do survive are unlikely to breed successfully. Over-collection can also affect local populations.

Tentacles sometimes in tight coils and curls.

Tuas, Apr 05

Cyrene Reef, Jun 12

With Peacock-tail anemone shrimp
(Periclimenes brevicarpalis)

Cyrene Reef, Mar 07

Tentacles in tight curls.

Beting Bronok, Aug 05

Body column purplish on the upper portion
and white on the lower.

Snaky anemones on Singapore shores

Photos of Snaky anemones for free download from wildsingapore flickr

Distribution in Singapore on this wildsingapore flickr map

Beting Bronok, Jun 17
Photo shared by Loh Kok Sheng on facebook.
East Coast Park, May 09
Photo shared by Loh Kok Sheng on flickr.

Terumbu Semakau, May 10
Photo shared by Loh Kok Sheng on his blog.
Lazarus Island, Nov 17
Photo shared by Rene Ong on facebook.
Pulau Semakau (South), Apr 2018
Photo shared by Jianlin Liu on facebook.

Terumbu Pempang Tengah, Nov 18
Photo shared by Juria Toramae 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 Hawai’ exclusive of the vertebrates Sea Challengers. 314pp.
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