Photo by Ettienne Kotze
Photo by Ettienne Kotze
Sock anemone. Photo Andrew Taylor.
Sock anemone. Photo Guido Zsilavecz
While this anemone is definitely not the sock anemone - the smooth column and large tentacles give that away, what species it is we actually do not know. Our initial thought was that it was the striped anemone Anthothoe stimpsoni (which may be A. chilensis), but the reference describes this as being a small animal - maybe 20 mm in diameter, whereas this one is clearly larger.
Ettienne mentioned that it was not attached to the rock, but instead it seemed to be attached to the caulerpa. This is also a bit odd, as it gives the impression the anemone only moved there relatively recently.
We will investigate a bit more, and spend some more time documenting the local anemones, as rather little is available with photos, making identification often very dificult.
Comments from Georgina Jones: It's officially known as Korsaranthus natalensis and was first described by Carlgren in 1938 (in the genus Condylactis). It is known to be a mobile anenome which attacks octocorals (corals and soft corals). It is not often seen in False Bay, being more frequently found further along the Garden Route and even there I get the impression it's not often seen. Dr Griffiths of the zoology department at UCT saw two of them when diving in the 70's off Miller's Point, and called them the candy striped anenome. He took them back to his aquarium and one way and another managed to forget them until after they had died in the tank. Nothing further was heard from the species until a somebody in Knysna took photos of it in the mid 90's. A specimen was then brought in and relaxed and dissected during which time it was realised a new genus was going to have to be erected to fit it in. It seems to like to eat octocorals, Dr. Griffiths saw it associated with one of those multicoloured sea fans.
Two Oceans, A guide to the marine life of Southern Africa, GM Branch, CL Griffiths, ML Branch and LE Beckley, 1994.
Thanks to Georgina Jones (and Dr. Griffiths) for further information.