Carpet flatworm (thysanozoon_brocchii_1)
Photo by Nick Turner
A whole congregation of carpet flatworms - 5 are pointed out in red.
Two more from the congregation on the same rock.
Freckled flatworm, a yet as undescribed species.
Two more freckled flatworms side by side
All other photos Guido Zsilavecz
Only a few flatworms are known from our waters, of which only one has been described. This is the most common one, the carpet flatworm, but a second one, the freckled flatworm, is also occasionally seen, although generally only in deeper waters.
The carpet flatworm has its dorsal surface covered densely by small papillae. At the front are two folds which resemble rhinophores, and hence this animal is often confused for a nudibranch, especially the gasflame nudibranch which is superficially similar.
Generally seen only single, in one unusual instance SURG member Guido Zsilavecz saw a whole group of them, ranging from tiny to fully grown, on a rock at the outer edge of Windmill.
For more details on the lifestyle and biology of flatworms, see "A field guide to the marine animals of the Cape Peninsula", available directly from SURG, as well as better dive stores and book stores in Cape Town.
A field guide to the Marine Animals of the Cape Peninsula, G Jones, 2008
Two Oceans, A guide to the marine life of Southern Africa, GM Branch, CL Griffiths, ML Branch and LE Beckley, 1994.