Orange-lined crowned nudibranch
Photo Geo Cloete
Orange-lined crowned nudibranch and crowned nudibranch mating?
Photo Andrew Taylor
The orange-lined crowned nudibranch can be distinguished from the "normal" crowned nudibranch Polycera capensis by having orange lines and spots along the flanks, and gills and rhinophores which are mostly white, with only the tips showing a grey-black. The gills may be topped by a bit of yellow. This contrasts to the crowned nudibranch, whose gills and rhinophores are all black, with the latter also possibly tipped in yellow. This species lacks the orange markings, and often has much bolder black lines. Given the consistency of these characteristics SURG believes that the orange-lined specimens may be a closely related, but different species. That is, until SURG member Andrew Taylor photographed what looks like individuals of each species about to mate. So, maybe they are only colour variations...
For more details on these nudibranchs, see "Nudibranchs of the Cape Peninsula and False Bay", available directly from SURG or leading Cape Town dive stores.
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.