Adult shaggy sea hare (Bursatella leachi africana), about 12 cm long.
Young shaggy sea hare, about 3 cm long.
Close-up of a juvenile, showing the beautiful spots and pattern. Adults have the spots as well, although more hidden.
Spotted sea hare (Aplysia oculifera).
All photos Guido Zsilavecz
Two moderately rare species have suddenly become common at Long Beach. These are the spotted sea hare, Aplysia oculifera, which can be distinguished from other sea hares by having white-centred black spots, as well as the shaggy sea hare, Bursatella leachi africana. The latter is known to have sporadic population explosions, something SURG members have seen in Knysna, but not yet in False Bay. Now, in certain areas, many of different sizes can be found. They ingest sand and filter out any edible algae, and are hence found on sandy areas. These sea hares turned out to be much more beautiful when viewing the images than underwater, as a pattern of small black spots and some bright ocellate spots reveals itself between the shaggy coat. This was especially prominent on younger individuals, which have a less dense covering.
All photos shown are of different individuals.
The spotted sea hare also feed on algae, but prefer "larger" ones, such as Caulerpa and others, and are usually found in close proximity to such algae. They have an unusual defense mechanism, in that they can secrete a purple dye when disturbed. They may also "fly" by flapping their large parapodia, but only do so rarely. Adults and juveniles were found, and some were clearly mating.
For more details see "Nudibranchs of the Cape Peninsula and False Bay", now available from SURG and better Cape Town dive shops.
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.