The "dinosaur" nudibranch Melibe liltvedi
The cowled nudibranch Melibe rosea
Both photos Guido Zsilavecz
This nudibranch was discovered in 1987, and is listed in Gosliner's book as "Melibe sp.", although it was described shortly thereafter, and named in honour of Dr. William Liltved, a colleague of Gosliner and an expert on cowries. The species is usually found offshore, in deeper waters, and has recently been seen twice, at two different dive sites near Vulcan Rock, in about 25-30m. Compared to the cowled nudibranch, Melibe rosea, which is rarely seen at diving depths but is common in tide pools, the "dinosaur" nudibranch (named after stegosaurus), is much more conspicuous.
Both species feed by extending their cowl to trap small amphipods and isopods, or anything else that may be edible.
Nudibranchs of Southern Africa - a guide to the opisthobranch molluscs of southern Africa, T Gosliner, 1987.