Halgerda carlsoni
Rudman, 1978

Order: NUDIBRANCHIA
Suborder: DORIDINA
Family: Dorididae

DISTRIBUTION

Tropical Western Pacific.

PHOTO

Koumac, New Caledonia, October 1993. PHOTO: Bill Rudman.

One of a group of species with a white background and orange markings, Halgerda carlsoni is characterised by the orange-tipped rounded tubercles and the scattering of small orange specks all over the mantle between the tubercles. There is a band around the mantle edge devoid of small orange specks. The gills and rhinophores are speckled with black and in some animals the speckling can be dense leading to some sections of th gills being almost completely black. Other similar coloured species include Halgerda malesso, Halgerda sp. 1 and Halgerda aurantiomaculata.

Reference:
• Rudman, W.B. (1978). The dorid opisthobranch genera Halgerda and Sclerodoris Eliot from the Indo-West Pacific. Zoological Journal of the Linnean Society, 62: 59-88.

Authorship details
Rudman, W.B., 1999 (February 4) Halgerda carlsoni Rudman, 1978. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/halgcarl

Related messages


Re: Halgerda carlsoni from East Africa

February 10, 2009
From: Sully et Monika Bachel


Concerning message #2015:

Hello Bill

Here are 3 Halgerda carlsoni observed at "Ile Ste Marie" on the East Coast of Madagascar.

The orange colour seems to be more brilliant and the black rhinopores look different than the East Africa Halgerda.

Locality: Ile Ste Marie, 15 - 20 m, Madagascar, Indian Ocean, october 2008. Length: 20 - 40 mm. Photographer: Sully Bachel.

These Halgerda seem to be common on this island.

Best regards
Sully

s.bachel@orange.fr

Bachel, S., 2009 (Feb 10) Re: Halgerda carlsoni from East Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22233

Dear Sully,

I suspect the paler colour in the photos of the animals from Tanzania are because they are a little over exposed. A photo from Sth Africa [message #3623] shows a much brighter coloured animal. All the western Indian Ocean animals, including yours, show the black on the gills and rhinophores as lines, while animals from the Pacific have black spots, so the two may turn out to be distinct species.

Best wishes,
Bill Rudman

Rudman, W.B., 2009 (Feb 10). Comment on Re: Halgerda carlsoni from East Africa by Sully et Monika Bachel. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22233

Halgerda carlsoni from Philippines

October 1, 2008
From: Marcel Tanke

Concerning message #21570:

Dear Bill and Carrie,

Your message of 19 September 2008 (picture taken at 24 Dec. 2008?? :-)) triggered me to check my own pictures of, what I had labeled as, H. batangas. And sure enough, I found new species for my species list. I will make 2 other separate messages on this [#21916, #21917 ].
The picture attached here is, I believe, Halgerda carlsoni. In enlargement the fine spots allover the mantle are clearly visible.

Locality: Dive site Sunken Island, Moalboal, 25 meters, Cebu Island, Philippines, 2 May 2008. Length: about 5 cm. Photographer: Marcel Tanke.

Best regards,
Marcel

marceltanke@cs.com

Tanke, M.A., 2008 (Oct 1) Halgerda carlsoni from Philippines. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21915

Dear Marcel,

Yes this is H. carlsoni.

Best wishes,
Bill Rudman

Rudman, W.B., 2008 (Oct 1). Comment on Halgerda carlsoni from Philippines by Marcel Tanke. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21915

Halgerda carlsoni from Malaysia

August 8, 2003
From: Francis & Pirjo Pellet

Dear Bill,
We found these Halgerda in Kapalai, Malaysia, 22nd of May 2003. Dive site "Mantis Ground", depth 14m. It seems to us that we have two different species. Could the photo here be of Halgerda carlsoni ( size 4 cm) and the one in the separate message be Halgerda batangas ( size 7 cm).

Best regards.
Francis and Pirjo

pirjo.pellet@free.fr

Pellet, F. & P., 2003 (Aug 8) Halgerda carlsoni from Malaysia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/10629

Dear Francis & Pirjo,
Yes this is Halgerda carlsoni, and your other photos are of Halgerda batangas. It's nice to get a photo of Halgerda with its gills fully extended, because it shows how sparse the pinnae are on the gills of species of this genus.
Best wishes,
Bill Rudman

Rudman, W.B., 2003 (Aug 8). Comment on Halgerda carlsoni from Malaysia by Francis & Pirjo Pellet. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/10629

Halgerda carlsoni from Fiji

June 26, 2003
From: Mary Jane Adams


Hi Bill,

I found this slug under a slab of rubble near Gau Island, Fiji on May 14, 2003. I believe it is Halgerda carlsoni. The enlargement shows the fine orange stippling and some damage to the mantle.

Length: about 20mm
Depth: about 15 meters

Best regards,
Mary Jane

divepng@yahoo.com

Adams, M.J., 2003 (Jun 26) Halgerda carlsoni from Fiji. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/10141

Thanks Mary Jane,
Bill Rudman


Halgerda carlsoni from Sulawesi

September 5, 2001
From: Mary Jane Adams

Hi Bill,
I believe this is Halgerda carlsoni. Length: 18 mm, Depth: 10 meters.

Divesite: Palua Abadi, Lembeh Straits, Sulawesi, Indonesia,
Aug. 10, 2001

Best regards,
Mary Jane

divepng@yahoo.com

Adams, M.J., 2001 (Sep 5) Halgerda carlsoni from Sulawesi. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5191

Dear Mary Jane,
I am pretty sure this is H. carlsoni, but the small orange spots on the mantle are not very much in evidence.
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Sep 5). Comment on Halgerda carlsoni from Sulawesi by Mary Jane Adams. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5191

Tonga Records: Halgerda carlsoni

May 29, 2001
From: Don Barclay


Dear Bill,
Here is another one for you, Halgerda carlsoni if I'm not mistaken. This nudibranch was found on rubble in 10 meters of water across the channel from the Tongan Beach Resort, Utungake Island, Vava'u, Tonga. It was found about noon on 16 February 2001. Size 25mm.

Take care,
Don

n5ols@samoatelco.com

Barclay, D., 2001 (May 29) Tonga Records: Halgerda carlsoni. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/4405

Dear Don,
Yes this is Halgerda carlsoni.
Best wishes,
Bill Rudman


Halgerda carlsoni from South Africa

March 7, 2001
From: Valda Fraser


Dear Bill
I'm not sure about this Halgerda. Please help!
Locality: Sodwana, north coast KwaZulu-Natal, SOUTH AFRICA - 18m
Date: Jan 2001
Size: 70mm
Thanks.
Regards
Valda Fraser

valda fraser@mweb.co.za

Fraser, V., 2001 (Mar 7) Halgerda carlsoni from South Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3623

Almost exactly a year ago I posted a message from Bernard Picton reporting Halgerda carlsoni from Tanzania, the first record from the western Indian Ocean. Your animal seems identical to Bernard's. They differ from western Pacific specimens in having black lines on the gills and rhinophores rather than spots, but in your photo the lines on the rhinophores seem to be aggregated spots so perhaps the difference is more apparent than real. It is an interesting find.
Best wishes,
Bill Rudman

Rudman, W.B., 2001 (Mar 7). Comment on Halgerda carlsoni from South Africa by Valda Fraser. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3623

Halgerda carlsoni from East Africa

March 5, 2000
From: Bernard Picton


Dear Bill,

Here is another Halgerda. It is a picture of H. carlsoni from Pemba Is., Tanzania in February 1999, with a close-up of the speckled orange pattern of spots.

Best wishes,

Bernard

bernard.picton.um@nics.gov.uk

Picton, B., 2000 (Mar 5) Halgerda carlsoni from East Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2015

Thanks Bernard,
I had previously thought of this species as a Western Pacific animal. I am not sure how important the colour of the gills and rhinophores are in this species but in western Pacific H. carlsoni the gills and rhinophores are white with small black spots and some traces of a line along the gill rachis. In your animal there seems to be a black line up the posterior side of the rhinophore stalk and black bands up each side of the club. The gills have no spots but a heavy black line along the rachis. Whether these differences are important or not will obviously need some more information on colour variation in the species and anatomical infomation.

A species identified in Sea Slugs of Western Australia [Fig 129] as Halgerda cf. carlsoni [and elevated to Halgerda carlsoni in Debelius's book], differs in having no fine orange spots and having a black rhinophore club and black-lined gills.

Best wishes,
Bill Rudman.

Rudman, W.B., 2000 (Mar 5). Comment on Halgerda carlsoni from East Africa by Bernard Picton . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2015