Two four-colour nudibranchs.
And is this what they are after - tubeworms? The tube is clearly visible, with two thin tentacles sticking out of each tube.
All photos Guido Zsilavecz.
Usually quite rarely seen, and then only seen in singles, over the last few weeks many of these vibrantly-coloured aeolid nudibranchs could be found at Long Beach, Simon's Town. Just inshore of the barge, towards the pipeline, an area of sand must have shifted, leaving behind it a bed of small tubeworms - the whole area now looks like it is covered in bristles. On these several dozen four-colour nudibranchs were seen, from tiny ones up to fully grown 3 cm-long ones, crawling about. These nudibranchs are known to be quite voracious predators of other nudibranchs and anemones, but could these tubeworms possibly be their intended prey? Or is it something we cannot see?
Four-colour nudibranchs can be found on both sides of the Peninsula, from inshore down to at least 15m, and on a variety of surfaces - from reef, to algae growing out of sand, to kelp areas and patches of bryozoans. As mentioned, they are not common, and rarely are more than one seen anywhere near each other.
For further details on this and other nudibranchs, see "Nudibranchs of the Cape Peninsula and False Bay", available directly from SURG and better dive shops and books stores in Cape Town.
Nudibranchs of the Cape Peninsula and False Bay, G Zsilavecz, 2007
Nudibranchs of Southern Africa - a guide to the opisthobranch molluscs of southern Africa, T Gosliner, 1987.