Sebadoris nubilosa
(Pease, 1871)

Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Discodorididae

DISTRIBUTION

Tropical Indo-West Pacific

PHOTO

Hurghada, El Eruk, Egypt. Red Sea. Depth: 10 m. Length: ca. 20 cm. 8 November 2005. sand bottom. Photographer: Marc ? [from Sven Kahlbrock #15283]

Sebadoris nubilosa can be characterised externally by its relatively soft mantle, covered with soft pointed tubercles, mottled with light brown colours and a few small dark brown patches. The underside of the mantle is translucent white with a distinct submarginal dark-brown band. Between this band and the body are scattered large brown spots. The sides and sole of the foot are translucent white with dark brown spots. The animal can swim if disturbed and autotomise the whole or part of the mantle skirt. The penis is armed with spines and when retracted has a characteristic spiral shape.

Kay & Young's (1969) report from Hawaii is most probably incorrect as their animal apparently had an unarmed penis.

  • Eliot, C.N.E. (1904) On some nudibranchs from East Africa and Zanzibar. Part III. Dorididae Cryptobranchiatae, I. Proceedings of the Zoological Society of London, 1903(2): 354-385, Pls.32-34.
  • Eliot, C.N.E. (1906): On the nudibranchs of Southern India and Ceylon, with special reference to the drawings by Kelaart and the collections belonging to Alder & Hancock preserved in the Hancock Museum at Newcastle-on-Tyne. Proceedings of the Zoological Society of London [for 1906], 2, 636-691. (Pls. 42-47)
  • Edmunds, (1971): Opisthobranchiate Mollusca from Tanzania (suborder Doridacea). Zoological Journal of the Linnean Society 50(4), 339-396. (Pl.1)
  • Kay, E.A. & Young, D.K. (1969) The Doridacea (Opisthobranchia: Mollusca) of the Hawaiian Islands. Pacific Science, 23(2): 172-231
  • Marcus, Er. & Marcus, Ev (1960) Opisthobranchia aus dem Roten Meer und von den Malediven. Akademie der Wissenschaften und der Literature, Abhandlungen der Mathematisch-Naturwissenschaftlichen Klasse 12, 873-933.
  • Marcus, Er. & Marcus, Ev. (1970) Opisthobranch mollusks from the southern tropical Pacific. Pacific Science, 24(2): 155-179..
  • Pease, W.H. (1871) Descriptions of new species of Nudibranchiate Mollusca inhabiting Polynesia. No.2. American Journal of Conchology. 7 (1): 11-19
Authorship details
Rudman, W.B., 2005 (November 17) Sebadoris nubilosa (Pease, 1871). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/sebanubi

Related messages


Sebadoris nubilosa from Reunion Island

August 4, 2008
From: Hugues Flodrops


Concerning message #19446:

Dear Bill,
Here are some pictures of Sebadoris nubilosa. One of them shows it's distinctive underside with submarginal dark-brown band. I hope it's interesting for the Forum to confirm its Indian Ocean distribution.

Locality: Saline Lagoon, 2 metres, Reunion Island, Indian Ocean, 28 December 2007, Night. Length: 200 mm. Photographer: Hugues Flodrops.

Best regards.
Hugues.

hugues.flodrops@wanadoo.fr

Flodrops, H., 2008 (Aug 4) Sebadoris nubilosa from Reunion Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21405

Thanks Hugues,

I suspect this species is often overlooked as it is so well camouflaged on sand and shell grit. As you say, the submarginal brown band on the underside of the mantle distinguishes it from other large dorids with brown spots on the underside. Other distinguishing external features are the soft pointed papillae on the mantle and the thin folded edge to the mantle - much like in some species of Dendrodoris. 

Best wishes,
Bill Rudman

Rudman, W.B., 2008 (Aug 4). Comment on Sebadoris nubilosa from Reunion Island by Hugues Flodrops. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21405

Sebadoris nubilosa from the nthn Mariana Islands

February 28, 2007
From: Yukari Tani


Dear Dr.Bill,
I attach 3 pictures.
We think this animal is Sebadoris nubilosa.

Locality: Lau Lau Beach, 6m, Saipan, Northern Mariana Islands,, Pacific Ocean, 12 January 2007, under the dead coral. Length: 120mm. Photographer: Yukari Tani.

Would you give us your advice, please ?
Best regards,
Gon

dswith@isletwind.com

Yukari Tani, 2007 (Feb 28) Sebadoris nubilosa from the nthn Mariana Islands. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19446

Dear Gon,

Yes this is Sebadoris nubilosa. The large crowded papillae on the mantle I quite characteristic of this species and it differs from similar looking species of Discodoris in having a fleshier, softer mantle skirt. In photos it looks quite look Dendrodoris tuberculosa but they can be easily distinuished by the colour of the underside of the mantle and foot. In fact Sebadoris nubilosa is instantly recognisable from its ventral colour pattern. There are many species with a translucent whitish underside with brown spots, but this species is the only one I know with a brown submarginal band around the mantle edge, so beautifully shown in lower photo

Best wishes,
Bill Rudman

Rudman, W.B., 2007 (Feb 28). Comment on Sebadoris nubilosa from the nthn Mariana Islands by Yukari Tani. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19446

Sebadoris nubilosa from Heron Island

December 1, 2005
From: Julie Marshall


Dear Bill,

Following the pictures of Sebadoris nubilosa from the Red Sea and the Maldivies I am attaching some photos of this species from Heron Island [Great Barrier Reef] including one of its distinctive underside of the mantle. The first animal was found at night on the reef platform in December 1996 and measured 200 mm. The second animal was also found on the reef platform in the late afternoon crawling across coral in December 1998 and measured 230 mm.

Locality: Heron Island, Great Barrier Reef, Queensland, Australia. Intertidal. Length: Upper photos: 200 mm [6 December 1996]; Lower photo: 230 mm, [5 Dec. 1998]. Photographer: Julie Marshall

Best wishes,
Julie Marshall

juliemarshall@netspace.net.au

Marshall, J.G., 2005 (Dec 1) Sebadoris nubilosa from Heron Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15387

Dear Julie,
Thanks for these photos. especially the photo of the underside which is very characteristic of the species.
Best wishes,
Bill Rudman

Rudman, W.B., 2005 (Dec 1). Comment on Sebadoris nubilosa from Heron Island by Julie Marshall. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15387

Brown 'Spanish Dancer' in Maldives

November 29, 2005
From: Mirta Moraitis

Dear Bill
From Indonesia I live now in the Maldives and few days ago during a night dive in the lagoon we found a big Nudibranch swimming (15 cm). It is the first time that I see a Spanish Dancer like this. I think is a Spanish Dancer but I'm not sure because of the color.

Locality: Velavaru Island Resort, Maldives, Indian Ocean. Depth: 2 mt. Length: 15 cm. 26 November 2005. sandy. Photographer: Mirta Moraitis

Sorry for the very bad picture.
Thank you very much for your help
Mirta Moraitis

dipingu74@hotmail.com

Moraitis, M., 2005 (Nov 29) Brown 'Spanish Dancer' in Maldives. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15383

Dear Mirta,

Not all large swimming dorids are Hexabranchus. This is Sebadoris nubilosa. It's quite a coincidence you finding it recently, as it is only a few days since we had our first message [#15293] about this species. It can grow quite large, can swim by flapping its mantle skirt, and can also break off much of the mantle skirt when disturbed [see autotomy page]. It looks like a species of Discodoris but the soft pointed papillae all over the mantle are quite characteristic.

Best wishes,
Bill Rudman

Rudman, W.B., 2005 (Nov 29). Comment on Brown 'Spanish Dancer' in Maldives by Mirta Moraitis. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15383

Dendrodoris? from Red Sea

November 18, 2005
From: Sven Kahlbrock


Hello,
I.m working as diving instructor at Hurghada in the Red Sea, Egypt. Last week we found this probable Dendrodoris. I would like to know if there is any further information that you have about this species. At  first it looked like Dendrodoris tuberculosa, but the tubercles are not that big.

Locality: Hurghada, El Eruk, Egypt. Red Sea. Depth: 10 m. Length: ca. 20 cm. 8 november 2005. sand bottom. Photographer: Marc ?

Thank you for the help, with best regards
Sven Kahlbrock

s_kahlbrock@web.de

Kahlbrock, S., 2005 (Nov 18) Dendrodoris? from Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15293

Dear Sven,
This is Sebadoris nubilosa. It has a much softer body than  Dendrodoris tuberculosa and as you noticed, it is covered in pointed papillae, rather than large tubercles. It can break off part of its mantle when threatened, and can also swim. It is usually well camouflaged on coral sand and coral rubble backgrounds.
Best wishes,
Bill Rudman

Rudman, W.B., 2005 (Nov 18). Comment on Dendrodoris? from Red Sea by Sven Kahlbrock. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15293