Tag: Corals and Anemones (Anthozoa)

Although related to the free-swimming, gelatinous "jellyfish" under the phylum Cnidaria, the species contained within this gallery are very different in appearance.

Corals and Sea Anemones differ mainly from other Cnidarians in that they do not experience a "medusa" stage in their development.

Most Corals form colonies of polyps which are structurally similar to Anemones, although considerably smaller.

Anthozoa can be divided into two separate sub-classes which are:

  • Hexacorallia - contains the hard, stoney reef-building Corals, the Sea Anemones and the tube dwelling Anemones.
  • Octocorallia - includes the "soft Corals", Sea Pens, Whip Corals and Sea Fans (Gorgonians).

Although related to the free-swimming, gelatinous "jellyfish" under the phylum Cnidaria, the species contained within this gallery are very different in appearance.

Corals and Sea Anemones differ mainly from other Cnidarians in that they do not experience a "medusa" stage in their development.

Most Corals form colonies of polyps which are structurally similar to Anemones, although considerably smaller.

Anthozoa can be divided into two separate sub-classes which are:

  • Hexacorallia - contains the hard, stoney reef-building Corals, the Sea Anemones and the tube dwelling Anemones.
  • Octocorallia - includes the "soft Corals", Sea Pens, Whip Corals and Sea Fans (Gorgonians).
Alan's picture
Magnificent Anemone (Heteractis Magnifica) with Pink Anemonefish (Amphiprion Perideraion)

A Pink Anemonefish (Amphiprion Perideraion) settles into its host Magnificent Anemone (Heteractis Magnifica) as the early evening sunlight begins to fade over Mae Haad/Koh Ma reef.

Alan's picture
Brown-Barred Grouper (Cephalopholis boenak)

Another photo of a Brown-Barred Grouper (Cephalopholis boenak) resting amongst some Hairy Mushroom Anemones (Rhodac

Alan's picture
Brown-Barred Grouper (Cephalopholis boenak)

A Brown-Barred Grouper (Cephalopholis boenak) resting amongst some Hairy Mushroom Anemones (Rhodactis indosinensis) at

Alan's picture
Hairy Mushroom Anemone (Rhodactis Indosinensis)

Evidence of the nasty sting that can be inflicted by members of the Cnidaria family which includes Jellyfish, Corals and Sea Anemones.

Alan's picture
Hairy Mushroom Anemone (Rhodactis Indosinensis)

In this photograph of the species i've tentatively identified as the Hairy Mushroom Anemone (Rhodactis Indosinensis), the pedal disk or foot can be seen attached to a red encrusting sponge, possibly Clathria Mima or Monanchora Barbadensis.

Alan's picture
Hairy Mushroom Anemone (Rhodactis Indosinensis)

Although tentatively identified as the Hairy Mushroom Anemone (Rhodactis Indosinensis), i am far from certain that this is correct.

Alan's picture
Elephant's Ear Anemone (Amplexidiscus Fenestrafer)

This photograph, taken at Sail Rock, shows the underside of an Elephant's Ear Anemone (Amplexidiscus Fenestrafer) and its method of attaching itself to a suitable surface by means of a powerful pedal disk or "foot" as it is more commonly known.

Alan's picture
Elephant's Ear Anemone (Amplexidiscus Fenestrafer)

This photo shows the characteristic parallel ridges which form a margin around the flat, tentacle-covered disc of the Elephant's Ear Anemone (Amplexidiscus Fenestrafer).

Alan's picture
Elephant's Ear Anemone (Amplexidiscus Fenestrafer)

This photo shows an Elephant's Ear Anemone (Amplexidiscus Fenestrafer) forming a characteristic ball.

This would suggest that the anemone has caught a prey item (most likely a small fish) within its stinging tentacles and is in the process of maneuvering it towards the central mouth.

Alan's picture
A Colony of Magnificent Anemones (Heteractis Magnifica) at South-West Pinnacles, Koh Tao

One of the most striking features at South West Pinnacles are the beautiful colonies of