Whip-fan nudibranch out of its habitat.
Photo by Dieter Stegemann
Whip-fan nudibranch on a fan.
More conspicuous as it moves from branch to branch.
A pale variant.
Photos Guido Zsilavecz
This small nudibranch is not uncommon, but only rarely seen, as it is extremely well camouflaged. All of them live on various sea fans of the genus Eunicella, some of which may be a deep orange, some a pale cream, nearly white. The nudibranch has a similar colour, so seeing a white one is not unusual. Normally they are curled around a branch of the sea fan, and given their colour and texture look like thickened parts of the fan. Only when they move from branch to branch, or occasionally when they are not on a fan, are they more conspicuous. Egg masses are a zig-zag set of coils around a branch.
For more details, see "Nudibranchs of the Cape Peninsula and False Bay", available directly from SURG, and better dive stored in Cape Town.
Nudibranchs of the Cape Peninsula and False Bay, G. Zsilavecz, 2007.