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Phylum Cnidaria > Class Anthozoa > Order Actiniaria > Genus Stichodactyla
Merten's carpet anemone
Stichodactyla mertensii
Family Stichodactylidae
updated Nov 2019
Where seen? This enormous carpet anemone with short fat tentacles is sometimes seen on our undisturbed Southern shores.

Features: Diameter to 1m or more. The large oral disk covered with short tentacles so that it resembles a carpet. The oral disk is often held flat against the surface, unlike the Giant carpet anemone (Stichodactyla gigantea) in which the oral disk is often folded. Small pedal disc frequently attached in crevice. The anemone can retract but not rapidly.

Body column tan to white with bumps (verrucae) that are adhesive and appear as rows of spots, generally in magenta or orange (which may appear purplish at depth). No verrucae below wide upper column, but splotches of pigment continue down short, narrow column in more or less longitudinal streaks.

The tentacles are not adhesive, club-shaped to finger-like. All tentacles may be short (10-20 mm long), or some (in patches) very long (to 50 mm or more). It does not have a fringe of long-short tentacles at the edge of the oral disk like Haddon's carpet anemone (Stichodactyla haddoni).

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

Carpet food: Carpet anemones harbour symbiotic single-celled algae (called zooxanthellae). The algae undergo photosynthesis to produce food from sunlight. The food produced is shared with the anemone, which in return provides the algae with shelter and minerals. The zooxanthellae are believed to give tentacles their brown or greenish tinge. Carpet anemones may also feed on fine particles that are trapped on their bodies. These anemones have not been observed to eat large animals.

Giant friends: Besides the symbiotic algae that lives inside the their tentacles several kinds of animals have been associated with Merten's carpet anemones. These anemonefishes (Amphiprion sp.) including A. akallopisos, A. akindynos, A. allardi, A. chrysogaster, A. chrysopterus, A. clarkii, A. fuscocaudatus, A. latifasciatus, A. leucokranos, A. ocellaris, A. sandaracinos, A. tricinctus. But so far, the only animals observed on Merten's carpet anemones were the Five-spot anemone shrimps (Periclimines brevicarpalis) and the Clown anemonefish.

Status and threats: Carpet anemones are 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. 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.

Terumbu Hantu, Apr 12

Pulau Jong, Apr 11

Merten's carpet anemones on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores

Small Sisters Island, May 18
Photo shared by Abel Yeo on facebook.

Small Sisters Island, Jul 23
Photo shared by Kelvin Yong on facebook.

Terumbu Hantu, Jun 16
Photo shared by Rene Ong on facebook.

Terumbu Hantu, Jun 16
Photo shared by Rene Ong on facebook.

Pulau Jong, Apr 15
Photo shared by Neo Mei Lin on her blog.

Pulau Jong, Jun 17
Photo shared by Richard Kuah on facebook.

Terumbu Hantu, Jun 16
Photo shared by Rene Ong on facebook.

Pulau Semakau North, Sep 23

Photo shared by Marcus Ng on facebook.

Pulau Semakau North, Jul 20

Photo shared by Loh Kok Sheng on facebook.

Terumbu Bemban, Apr 11

Photo shared by Loh Kok Sheng on his blog.

Terumbu Bemban, Jul 18

Photo shared by Abel Yeo on facebook.

Raffles Lighthouse, Sep 10
Photo shared by Toh Chay Hoon on her blog.

Raffles Lighthouse, Sep 10
Photo shared by Neo Mei Lin

Pulau Senang, Jun 10

With anemone shrimp.
Photo shared by Loh Kok Sheng on his flickr


Other references

  • 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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