The walking anemone (or sock anemone, or hedgehog anemone – Preactis millardae) is endemic to Cape waters and I’ve only seen it on the Smitswinkel Bay wrecks so far. It has been seen as far east as Port Elizabeth.
It likes deeper water, 10-30 metres. Instead of being attached to a rock or the sand (sessile), these creatures walk about with a movement like a slinky or caterpillar. Their favourite food is multicoloured sea fans, so instead of waiting for a snack to drift by (like most anemones do), walking anemones actually have to move about to find their next meal. If you look carefully you can see how the anemone in the picture above has eaten the red sea fan to its left down to the skeletal supports (like little twigs). They also like soft corals.
Their bodies can stretch out to resemble a sock, but in these pictures they are scrunched up. The mouth has red lines radiating outward from it. The first time I saw one of these I thought it was a grubby orange gas flame nudibranch, because I couldn’t see the mouth stripes. Revisiting that picture (below) in light of the new specimens I’ve seen since has confirmed that it was a walking anemone and not a nudibranch!
SURG has some information about walking anemones here and here.
