Halgerda brunneomaculata
Carlson & Hoff, 1993

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

DISTRIBUTION

Known from Japan, Guam, Great Barrier Reef, Rarotonga.

PHOTO

Ngatangiia, 10 metres, Rarotonga, Cook Islands, South Pacific, 20 September 2002, Coral reef. Length: 10 mm approx. Photographer: Graham McDonald.

The ground colour of the animal is translucent white often tinged with pale yellow. The dorsum is covered with a network of raise narrow ridges which are edged in a deeper yellow. In some animals the background colour of the mantle is a deeper yellow and the ridges cannot be easily distinguished. There are large rounded brownish black spots scattered over the dorsum, between the ridges. Irregular dark brown spots occur on the posterior part of the foot and along the sides, and there are small spots running along the junction of the sides of the body and the mantle.  The rhinophores are translucent white with a dark brown line up each side of the stalk and the club. The gills are also translucent white with a brown line up the inner edge.

Animals are reported to reach at least 25 mm in length.

Carlson, C. H. and Hoff, P. J. (1993) Three new Halgerda species (Doridoidea: Nudibranchia) from Guam.  The Veliger, 36(1): 16-26.

Authorship details
Rudman, W.B., 2006 (June 30) Halgerda brunneomaculata Carlson & Hoff, 1993. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/halgbrun

Related messages


Re: Halgerda brunneomaculata from nthn Mariana Isla

March 2, 2007
From: Greg Moretti

Concerning message #17629:

I photographed this Halgerda brunneomaculata in Saipan, Northern Mariana Islands, at 0.1m depth. It was found in a dark, overhang covered tidepool near Forbidden Island. Length approximately 10 mm.

Locality: Forbidden Island, 0.1 m, Saipan, Commonwealth of the Northern Mariana Islands, Pacific, 17 February 2007, Intertidal. Length: 10 mm. Photographer: Greg Moretti.

Greg Moretti

moretti2@gmail.com

Moretti, G.S., 2007 (Mar 2) Re: Halgerda brunneomaculata from nthn Mariana Isla. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19522

Dear Greg,
Thanks for this photo. It is the first photo we have of a specimen with a translucent white background colour in which the yellow ridges can clearly be seen.
Best wishes,
Bill Rudman

Rudman, W.B., 2007 (Mar 2). Comment on Re: Halgerda brunneomaculata from nthn Mariana Isla by Greg Moretti. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19522

Halgerda brunneomaculata from nthn Mariana Islands

September 7, 2006
From: Yuji Fujie

Dear Dr.Bill,
I've found a Halgerda brunneomaculata.
We can find a number of different species of Halgerda at Grotto point.

Locality: Grooto, 15 m, Saipan, Northern Mariana Islands, Pacific Ocean, 29 July 2006, on the dead coral with Aglaophenia whiteleggei. Length: 10 mm. Photographer: Yuji Fujie.

Best regards,
Yuji

dswith@isletwind.com

Yuji Fujie, 2006 (Sep 7) Halgerda brunneomaculata from nthn Mariana Islands. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17629

Thanks Yuji,
It's good to get photos of these rarely recorded species.

Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Sep 7). Comment on Halgerda brunneomaculata from nthn Mariana Islands by Yuji Fujie. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17629

Re: Halgerda brunneomaculata from the Coral Sea

August 14, 2006
From: Philip Cromwell

Concerning message #17396:

Dear Bill,
From the picture it looks like there is a single brown stripe up the posterior side of each rhinophore. Wouldn't this exclude Halgerda brunneomaculata? I looked for another species with single brown lines up the back of the rhinophore, but they all seem to have orange tubercles at the vertex of the mantle ridges.

Cheers,
Phil

chiron42@sbcglobal.net

Cromwell, P.A., 2006 (Aug 14) Re: Halgerda brunneomaculata from the Coral Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17440

Dear Phil,
Yes I wondered about that, but I think the apparent single line is really just one of the two brown lines which run up each side of the rhinophore in typical H. brunneomaculata. The photo is a side view and I think we are seeing the right side of each rhinophore, rather than its back or posterior side.

Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Aug 14). Comment on Re: Halgerda brunneomaculata from the Coral Sea by Philip Cromwell. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17440

Halgerda brunneomaculata from the Coral Sea

August 12, 2006
From: Colin Gans

Hi Bill

Could you identify this nudibranch for me please.

Locality: Osprey Reef, 15m, QLD, Australia, Coral Sea, 05 June2005, coral reef. Photographer: Colin Gans.

Many thanks & regards,
Colin Gans

colin@gans.co.nz

Gans, C.L., 2006 (Aug 12) Halgerda brunneomaculata from the Coral Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17396

Dear Colin,
This is a species of Halgerda. I am pretty sure it is Halgerda brunneomaculataalthough in that species there is usually a thin yellow edge to each of the mantle ridges. However all the other external features seem to fit that species. It has similarities to H. maricola but the colour on the gills and rhinophores is quite different, and the edge of the foot and the mantle in that species is yellow.

Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Aug 12). Comment on Halgerda brunneomaculata from the Coral Sea by Colin Gans. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17396

Halgerda brunneomaculata from Rarotonga

July 1, 2006
From: Graham McDonald

Kia orana Bill,
Greetings from Rarotonga.
I found this nudbranch a while ago and can't find any reference to it.

Locality: Ngatangiia, 10 metres, Rarotonga, Cook Islands, South Pacific, 20 September 2002, Coral reef. Length: 10 mm approx. Photographer: Graham McDonald.

Thanks,
Graham

images@waterworx.co.ck

McDonald, G, 2006 (Jul 1) Halgerda brunneomaculata from Rarotonga. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17012

Dear Graham,
I am pretty sure this is Halgerda brunneomaculata. It normally has distinct yellow ridges forming a network over the mantle, like most species of Halgerda, but I suspect in a juvenile like yours the ridges are not yet well developed.

I just realised I didn't have a Fact Sheet for this species, so I have rectified that as well
Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Jul 1). Comment on Halgerda brunneomaculata from Rarotonga by Graham McDonald. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17012