Rostanga elandsia
Garovoy, Valdés & Gosliner, 2001
Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Dorididae
DISTRIBUTION
This species has been found from the Atlantic coast of the Cape Peninsula at Bakoven Bay to Rooi Els, beyond the eastern shore of False Bay. It has not been recorded outside South Africa.
PHOTO
Specimen from Bakoven Bay, South Africa. PHOTO: T.M.Gosliner
The living animal is bright red in colour, with several small black spots scattered on the dorsum. The perfoliate rhinophores are also bright red and are composed of 14 horizontal transverse lamellae. The gill has the same bright red colour as the rest of the body, and is composed of 10 bipinnate branchial leaves. The body shape is oval. The notum is covered with numerous broad and short caryophyllidia tubercles. Each caryophyllidium consists of an extremely wide, flattened, ciliated tubercle with small marginal cilia and five to six slightly taller, thick spicules surrounding the tubercle. The anal papilla lies within the circlet of the branchial plume. The anterior border of the foot is bilabiate and notched. The oral tentacles are well formed, and appear conical in shape. Preserved specimens to 20 mm in length.
Rostanga elandsia is found from the mid-intertidal region to a depth of at least 30m. Associated intertidally with red sponges and subtidally on various different sponges.
Rostanga elandsia shares a background coloration with most of the Rostanga but is distinguishable anatomically. In Gosliner (1987) this species is known as Rostanga sp. 1. See Rostanga elandsia - Radula.
- Garovoy, J.B., Valdés, A., & Gosliner, T.M. (2001) Phylogeny of the genus Rostanga (Nudibranchia), with descriptions of three new species from South Africa. Journal of Molluscan Studies 67: 131-144.
- Gosliner, T. M. (1987) Nudibranchs of Southern Africa, a guide to the Opisthobranchs of southern Africa. Monterey, Sea Challengers. 136 pp.
Rudman, W.B., 2002 (February 13) Rostanga elandsia Garovoy, Valdés & Gosliner, 2001. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/rostelan
Related messages
Re: Rostanga from South Africa
November 6, 2006
From: Peter Southwood
Concerning message #18142:
A small correction on the range of Rostanga elandsia: Rooi-Els is on the eastern shore of False Bay, not beyond it.
I have seen many specimens of what is probably R. elandsia on the eastern shore of False Bay from Gordon's Bay to Rooi-Els, Many of them at a dive site we call Percy's Hole, just north of Rooi-Els. Almost always on red/orange sponges.
Cheers,
Peter Southwood
peter.southwood@telkomsa.net
Southwood, P., 2006 (Nov 6) Re: Rostanga from South Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/18201Thanks Peter,
My terminology "Rooi Els, beyond the eastern shore of False Bay" on the species' Fact Sheet is a direct quote from the paper in which the species was named. Although awkward, I assumed it was a pedantic way of saying that it is found off the coast of Rooi-Els. I guess the important thing is to try and indicate whether this species is one that is restricted only to South Africa, or perhaps restricted to the Atlantic coast of southern Africa, rather than a species from the Indo-West Pacific.
It would be interesting to get some photos of its egg ribbon if possible. From my work on Indo-West Pacific species, the shape of the egg mass and the size of the eggs can be a very valuable aid in identifying each species of this genus, and at this stage we haven't any information on any of the Sth African species.
-
Garovoy, J.B., Valdés, A., & Gosliner, T.M. (2001) Phylogeny of the genus Rostanga (Nudibranchia), with descriptions of three new species from South Africa. Journal of Molluscan Studies 67: 131-144.
Best wishes,
Bill Rudman
Re: Rostanga elandsia from South Africa
November 3, 2006
From: Georgina Jones
Concerning message #18142:
Dear Bill,
I am very happy to go with Rostanga elandsia as an ID even without internal investigation -- the animal was spotted very much in the range given. I'm also very glad to know what it is now called -- so much better than Rostanga sp.1!
Going back to egg ribbons...
Would you be interested in pictures of the egg ribbon of Leminda millecra? I have a pic of one laying eggs and then of the egg ribbon itself.
Best wishes
Georgina
gjones@icon.co.za
Jones, G.J., 2006 (Nov 3) Re: Rostanga elandsia from South Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/18195Dear Georgina,
A photo of Leminda and its egg ribbon would be very valuable. I'm afraid our knowledge of the life history of even the most common species is full of gaps so any photos and observations of sea slugs 'doing things' will always be welcome.
Best wishes,
Bill Rudman
Rostanga elandsia from South Africa
November 3, 2006
From: Georgina Jones
Concerning message #18127:
Hi again,
I had a closer look at the photo and I think you may be right.. the thing about this particular Rostanga is that it is an extremely good mimic of the red / orange sponges it preys on. I attach three pictures to show you how nicely it blends into the background. Unfortunately, as far as I know, it is undescribed, and is known here only as Rostanga sp.1.
Locality: False Bay, 10-20m, Western Cape, South Africa, False Bay, uncertain, sometime in 2005, red sponges on rocky reef. Length: less than 40 mm. Photographer: Upper & middle Photos 1, 2: Andrew Taylor. Lower Photo: Sharon Albert
Best wishes to you
Georgina
gjones@icon.co.za
Jones, G.J., 2006 (Nov 3) Rostanga elandsia from South Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/18142
Dear Georgina,
If you look at message #6237 you'll see that Gosliner's Rostanga sp. 1 is now Rostanga elandsia. Species of Rostanga are quite difficult to identify externally, but your animal seems to have the characteristic small black specks which seem to be an identifying feature of that species. We would really need to look at the internal anatomy of your species to be sure.
Many species of Rostanga feed on orange-red sponges and all of them are very similarly coloured and so well camouflaged.
Best wishes,
Bill Rudman
Rostanga from South Africa
February 16, 2002
From: A. Valdés & T. Gosliner
Dear Bill,
Terry Gosliner and I have gathered photographs of the species of Rostanga, R. elandsia, R. aureamala and R. phepha we described from South Africa with Jocelyn Garovoy two years ago, for you to include in the Forum's coverage of the genus.
• Garovoy, J. B., Valdés, A. & Gosliner, T. M. 2001. Phylogeny of the genus Rostanga (Nudibranchia), with descriptions of three new species from South Africa. Journal of Molluscan Studies, 67: 131-144.
Best regards,
Angel & Terry
Thanks Angel & Terry,
I have prepared pages on your three species:
Rostanga elandsia,
Rostanga aureamala,
Rostanga phepha
Bill Rudman
