Dendrodoris caesia. Photo Andrew Taylor
Flabellina capensis. Photo Andrew Taylor
Flabellina capensis. Photo Guido Zsilavecz
Cratena capensis size less than 10mm. Photo Andrew Taylor
Cratena capensis size less than 10mm. Photo Andrew Taylor
Cratena capensis. Photo Guido Zsilavecz
Melibe rosea. Photo Andrew Taylor
Melibe rosea. Photo Andrew Taylor
Mandelia mirocornata. Photo Andrew Taylor
Mandelia mirocornata. Photo Andrew Taylor
Mandelia mirocornata. Photo Guido Zsilavecz
Rhinophores of Mandelia mirocornata. Photo Guido Zsilavecz
Rhinophores of Bonisa nakaza. Photo Guido Zsilavecz
Rhinophores of Doto coronata. Photo Guido Zsilavecz
Rhinophores of Notobryon wardi. Photo Guido Zsilavecz
Dendrodoris caesia (the blue-speckled nudibranch) can be seen most often at places like A-Frame and Windmill, although it has been seen at Long Beach as well. See the Q and A section of 2005 for a few additional sightings and photos of this species.
Flabellina capensis (the white-edged nudibranch, named so because of white-edged, pointed and flattened cerata). This is a small nudibranch which can be found on both sides of the Peninsula and throughout False Bay. It is not common, and sightings are infrequent and unpredictable. It has been seen at Coral Gardens, Castle Rock, Percy's, Oudekraal, and as far afield as Knysna.
Cratena capensis (Named the white-tipped nudibranch in Two Oceans, but SURG thinks "orange-eyed" is better, due to its characteristic orange "eye-spots" just in front of the rhinophores - the "antenna", which are the two upright stalks, not the two pointing forward.) This nudibranch is surprisingly common, but often overlooked due to its small size. It can be found about anywhere along the Peninsula, from Oudekraal south to Coral Gardens, Castle Rocks, A-Frame and other Simon's Town dive sites, as well as Percy's and other Rooi Els divesites, and all along the coast to at least Knysna. Usually it has red cerata, but occasionally may have paler orange ones, as shown in Andrew's photos. The "eye-spots" are not often visible by the naked eye, but do show up on most photos if the angle is right.
Melibe rosea (The cowled nudibranch.) The wide "head" of this nudibranch is an extendable hood which is used to engulfing small crustacea like isopods and amphipods. For an excellent shot of this in action see the Two Oceans or Living Shores book. Some species of this genus have even bigger hoods than Melibe rosea - very impressive. This species is described as being one of the most common nudibranchs in the intertidal zone, and as such it seems to me that it really sticks to that zone, as it is actually very rare to see one at normal diving depths! I have seen a few at Coral Gardens (which is where Andrew has seen it as well), but nowhere else, even in shallow waters around Oudekraal, where I searched with my tank virtually sticking out of the water!
Mandelia mirocornata (Mandela's nudibranch.) This species, labeled Doriopsilla sp.1 in Gosliner's book, has since been described by Dr Terry Gosliner. The species defined a new genus, which he named Mandelia, in honour of Nelson Mandela. The species name, mirocornata, is "derived from the latin mirus (odd) and cornus (horn) in reference to the peculiar shape of the rhinophores of this species."
The peculiar shape of the rhinophores can be seen cleary in the close-up photo. The rhinophores, sensory organs used to detect food, are variable from genus to genus and even species to species within a genus (although often species with similar rhinophores are grouped together). Some rhinophores are simple smooth pointed stalks, others have lateral grooves, are knobbly or curled up, while others are protected by a "cup" or a sheath. Some of the interesting shapes are shown in the other photographs.
Gosliner's book records Mandelia mirocornata as occurring along at least the Atlantic seaboard, but we have seen it most often at Coral Gardens. Andrew first saw it at Stonehenge Reef, close to Maori Bay, and that is the first time I've heard of it being seen outside of Coral Gardens by another diver. It surprises us that at nearby Oudekraal, even after many dives over many years, we have not seen it! This although some areas seem to be very similar, if not the same, in terms of reef cover, as at Coral Gardens! At Coral Gardens itself it is quite common, and one regularly sees a few quite closely clustered together.
Nudibranchs of Southern Africa - a guide to the opisthobranch molluscs of southern Africa, T Gosliner, 1987.
Two Oceans, A guide to the marine life of Southern Africa, GM Branch, CL Griffiths, ML Branch and LE Beckley, 1994.
The living shores of Southern Africa, M Branch and G Branch, 1981.
www.museums.org.za/bio/molluscs/mandelia_mirocornata.htm