Austrodoris kerguelenensis
(Bergh, 1884)

Order: NUDIBRANCHIA
Suborder: DORIDINA
Family: Dorididae

DISTRIBUTION

Probably widespread around Antarctica and subantarctic islands. Known from Weddell & Ross Seas, Kerguelen Islands and the southern tip of South America.

PHOTO

McMurdo Sound, Antarctica. This photo is published with the permission of Norbert Wu from the Underwater Field Guide to Ross Island & McMurdo Sound, Antarctica .

Austrodoris kerguelenensis ranges in colour from white to bright yellow. It well illustrates the problems associated with studying the taxonomy of Antarctic nudibranchs. Every polar expedition brought back a few specimens which were worked on, usually by naturalists of the country from which the expedition originated. In most cases, no information on the colour or shape of the living animals were collected. As Heike Wagele has shown with Austrodoris, specimens from each expedition tended to be considered a distinct species. In the case of Austrodoris at least 14 names have been given to what Wagele now considers to be a single species! She shows that the variation in tubercle shape and size, alimentary canal and nerous system are clearly nothing more than intraspecific variation. This species has a widespread distribution around the Antarctic continent with many records from the Weddell and Ross Seas and as its name implies, from the sub-Antarctic Kerguelen Islands. There are also records from the southern tip of South America. The genus Austrodoris is apparently endemic to the Antarctic region and differs from Archidoris in details of the reproductive system. Dayton et. al.(1974) considers that Austrodoris kerguelenensis feeds, on the hexactinellid sponges (Rosella sp., Scolymastra sp.) as animals are often found sitting on large colonies, and juveniles are often found in the central cavity of the sponge colony. Barnes & Bullough (1996) report that at Signy Island (Scotia Sea) it feeds almost exclusively on the demosponge Dendrilla antarctica.

References:
• Barnes, D.K.A. & Bullough, L.W. (1996). Some observations on the diet and distribution of nudibranchs at Signy Island, Antarctica. Journal of Molluscan Studies 62, 281-287.
• Dayton, P.K., Robilliard, G.A., Paine, R.T. & Dayton, L.B. (1974). Biological accommodation in the benthic community at McMurdo Sound, Antarctica. Ecological Monographs, 44: 105-128.
• Garcia, F.J., Troncoso, J.S., Garcia-Gomez, J.C. & Cervera, J.L. (1993). Anatomical and taxonomical studies on the Antarctic nudibranchs Austrodoris kerguelenensis (Bergh, 1884) and A. georgiensis n.sp. from the Scotia Sea. Polar Biology, 13: 417-421.
• Wagele, H. (1987): The distribution of some Antarctic nudibranchs (Opisthobranchia). Journal of Molluscan Studies 53, 179-188.
• Wagele, H. (1989): Diet of some Antarctic nudibranchs (Gastropoda, Opisthobranchia, Nudibranchia). Marine Biology 100, 439-441.
• Wagele, H. (1990): Revision of the genus Austrodoris Odhner, 1926 (Gastropoda, Opisthobranchia). Journal of Molluscan Studies 56, 163-180.

Authorship details
Rudman, W.B., 1999 (February 9) Austrodoris kerguelenensis (Bergh, 1884). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/austkerg

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