Halgerda toliara
Fahey & Gosliner, 1999
Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Dorididae
DISTRIBUTION
Described from Madagascar, and reported here from South Africa.
PHOTO
UPPER: Park Rynie - 25m, south coast KwaZulu-Natal, SOUTH AFRICA. May 2000. Size: 15mm
LOWER: near Scottburgh. Depth: 25-28m, South Coast of Kwa Zulu Natal, South Africa. March 1999, Size: 40mm. PHOTOS: Valda Fraser.
Translucent white with pattern of reticulate yellow ridges. White gills tipped with black, and black rhinophore clubs. Fine yellow pustules around the mantle edge. Very similar externally to H. formosa. The main external differences are:
•H. formosa (Bergh, 1880) - yellow reticulate pattern - some black spotting around mantle skirt, and small whitish pustules near edge.
•H. toliara Fahey & Gosliner, 1999. - yellow reticulate pattern - no black spots on mantle, small yellow pustules near edge.
Reference:
• Fahey, S. & Gosliner, T.M. (1999) description of three new species of Halgerda from the western indian ocean, with a redescription of Halgerda formosa, Bergh, 1880. Proceedings of the California Academy of Sciences, 51(8): 365-383.
Rudman, W.B., 1999 (November 16) Halgerda toliara Fahey & Gosliner, 1999. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/halgtoli
Related messages
Re: Halgerda toliara? from Nosy Be Madagascar
January 21, 2009
From: Greg Regnier
Concerning message #19007:
This is a photo of Halgerda toliara also from Nosy Be, Madagascar.
Locality: Nosy Be, 30 feet, Madagascar, Indian Ocean, 27 October 2008. Length: 3 cm. Photographer: Greg Regnier.
Greg Regnier
gregnier.enteract@rcn.com
Regnier, G.A., 2009 (Jan 21) Re: Halgerda toliara? from Nosy Be Madagascar. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22166Dear Greg,
I would agree with your identification. The black rhinophore clubs and black-tipped unbranched gills seem to be characteristic of this species
Best wishes,
Bill Rudman
Halgerda toliara? from Nosy Be Madagascar
December 15, 2006
From: Ugo Gaggeri
Is it Halgerda toliara?
Locality: Nosy Be, 20 m, Madagascar, Indian Ocean, November 2006, coral. Length: 15 mm. Photographer: Ugo Gaggeri.
Thank very much for the help!
Ugo
ugogaggeri@hotmail.com
Gaggeri, U., 2006 (Dec 15) Halgerda toliara? from Nosy Be Madagascar. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19007Dear Ugo,
As you will see from looking at earlier messages concerning Halgerda toliara and Halgerda formosa I have had some difficulty in distinguishing some animals as one or the other. We know so little about variation in both species that new photos are always welcome. When I first saw your photo I thought that the extensive network of ridges on the mantle were very unusual for H. toliara, although the yellow median line was typical, and then I noticed what may turn out to be a good way to separate the two species. In your animal, the basal third of each gill is white while the upper two thirds is all black. This of course is not always obvious if the gills are not fully extended. if you look at photos of what we are calling H. formosa you will see that the gills are also black and white but the black is in the form of a black line along the inner edge of each gill, running right to the base of the gill and into the central circum-anal ridge. Gill colour is usually quite constant within a species so these quite obvious differences may be a useful way of separating animals which look a bit like both species
Your animal also raises the question again of whether H. toliara is a pale form of Halgerda wasinensis [see message #6223] ? Which is all very interesting to me but probably just a bit confusing to you. My advice would be to call it H. toliara, but remember that this is a work in progress - there is no final, definitive answer.
Best wishes,
Bill Rudman
Halgerda toliara? from Sth Africa
February 17, 2006
From: Colin Ogden
Hi Bill,
Am I right in the ID of this animal as Halgerd toliara. I found him in a cave, so maybe the lack of light as well as the diet might affect his colouration.
Locality: Sodwana Bay, 15m, South Africa, Indian, 9 Feb 2006, coral reef
Length: 30 mm. Photographer: Colin Ogden
Regards
Colin
scubaco@iafrica.com
Ogden C. M., 2006 (Feb 17) Halgerda toliara? from Sth Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15818
Dear Colin,
I'm afraid I have great difficulty in sounding authoritative over the identity of species of Halgerda. Sometimes I think there is a pattern emrging and other times I despair. I haven't seen a specimen of H. toliara which has a yellow background colour like this, and I haven't seen a Halgerda which changes from yelllow to white like this.
It is possible that it is H. toliara, certainly the raised tubercles around the mantle edge seem characteristic, but I suspect we are just going to have to wait until more is known about colour variability within populations.
Best wishes,
Bill Rudman
Halgerda toliara from Sth Africa
May 19, 2005
From: Colin Ogden
Hi,
I can't identify this nudi. Please can someone help.
Locality: Sodwana bay, South Africa, Indian Ocean. Depth: 18 metres. Length: 3 cms. April 2005. Coral reef. Photographer: Colin Ogden
Regards
Colin Ogden
scubaco@iafrica.com
Ogden, C., 2005 (May 19) Halgerda toliara from Sth Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13783Dear Colin,
I am pretty sure this is Halgerda toliara which is known from the western Indian Ocean
Best wishes,
Bill Rudman
Halgerda toliara from Mayotte
January 7, 2004
From: Marina Poddubetskaia
Dear Bill,
Here are some photos of Halgerda toliara from Mayotte. Both animals seem to be juvenile because larger specimens have already been seen in this nice lagoon.
Upper Photo:
Date: November 14, 2003
Location: Mayotte Island, Indian Ocean
Site: Choizil
Depth: 19m
Size: 13mm
Lower Photo:
Date: November 02, 2003
Location: Sada, Mayotte Island, Indian Ocean
Site: Passe Sada
Depth: 18.5m
Size: 8-10mm
Merry Xmas Bill !
Best wishes,
Marina.
nembro@nembro.info
Poddubetskaia, M., 2004 (Jan 7) Halgerda toliara from Mayotte. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/11744
Thanks Marina,
The absence of black spots and the opaque pustules around the mantle edge would seem to confirm your identification
Best wishes
Bill Rudman
Halgerda cf. toliara from Mayotte
January 7, 2004
From: Marina Poddubetskaia
Dear Bill,
In April I have sent you strange Halgerda photos from Mayotte, taken by Isabelle Ruffin [see message]. Last November, during my collecting mission there I saw 2 other specimens of this species.
The median yellow line and a raised yellow gill pocket seem to be constant characteristics of this variant. But also there can be some secondary yellow lines, like in the second specimen here.
There is a book dealing with marine fauna from Mayotte: Images & Magie du Grand Lagon, Frederique et Jean-Michel Maggiorani, 1991". In this book there is a photo of this Halgerda species with broken median line and some secondary yellow lines too.
I think that compared to usual Halgerda toliara (see my previous message), this variant seems to be a distinct species. What do you think about it ?
Upper Photo:
Date: November 06, 2003. Location: Mayotte Island, Indian Ocean. Site: Passe en S, buoy n° 2. Depth: 11.5m' Size: 15-17mm
Middle & Lower Photo:
Date: November 15, 2003. Location: Mayotte Island, Indian Ocean. Site: Passe en S, buoys n° 6&7. Depth: 6m. Size: 18mm
Cheers,
Marina.
nembro@nembro.info
Poddubetskaia, M., 2004 (Jan 7) Halgerda cf. toliara from Mayotte. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/11745
Dear Marina,
We still have a lot to learn about colour variations in these species as my messages today on colour variation in H. formosa and H. wasinensis, illustrate.
While these two animals in this message lack the reticulate pattern of the animals in your other message, the lower animal has traces of a reticulate pattern. As it is almost certainly related to the animal in the upper photo, they show a link between non-reticulate and reticulate specimens. At this stage I would suspect the animals in your two messages are the same species, but we need more material before we can say much more. Shireen Fahey may be able to give us more information on variability in H. toliara
Best wishes
Bill Rudman
Halgerda toliara? from Mayotte (1)
April 15, 2003
From: Marina Poddubetskaia
Dear Bill,
Here are some photos from Mayotte Island, Indian Ocean taken by Isabelle Ruffin [isabelle.ruffin@wanadoo.fr].
I can’t identify this Halgerda. Have you any idea which species is it ? It makes me think a little about Halgerda toliara.
Date: March 29, 2003
Site: Banc Jumeaux
Depth: 18m
Size: about 30mm
Photos: Isabelle Ruffin - www.biologie-marine.com
Thank you in advance for your help.
Best wishes,
Marina (and Isabelle).
nembro@nembro.info
Poddubetskaia, M., 2003 (Apr 15) Halgerda toliara? from Mayotte (1). [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9550Dear Marina & Isabelle,
This certainly looks like it could be a variant of H. toliara. I suspect we will only be able to sort this out when more material is available from throughout the Indian Ocean. Your animals differ in having a single yellow ridge down the midline, but they do agree in having the fine pustules around the mantle edge. Fahey & Gosliner describe them as yellowish pustules but if Valda Fraser's animal is correctly identified, it seems the pustules may be translucent and can appear white or yellowish. Perhaps Terry Gosliner or Shireen Fahey can give us their opinion. I am not sure if H. toliara has such a raised yellow gill pocket.
I have posted a couple more of your photos of this animal in a separate message.
Best wishes,
Bill Rudman
Halgerda toliara? from Mayotte (2)
April 15, 2003
From: Marina Poddubetskaia
Dear Bill,
Here are two more photos from to acompany the earlier message.
The data is the same:
Mayotte Island, Indian Ocean. Photos: Isabelle Ruffin - www.biologie-marine.com
Date: March 29, 2003
Site: Banc Jumeaux
Depth: 18m
Size: about 30mm
Best wishes,
Marina (and Isabelle).
nembro@nembro.info
Poddubetskaia, M., 2003 (Apr 15) Halgerda toliara? from Mayotte (2). [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9551Thanks,
Bill Rudman
Halgerda toliara from South Africa
June 24, 2002
From: Sean Sequeira
Dear Bill
I am new to your forum and I find your seaslug site very informative. This nudibranch was the size of the nail of my little finger, about 5mm in diameter. It was located behind a coral which was swaying in the surge, so much that I could only get this particular picture in clear focus. This photo was taken at Sodwana [east coast South Africa] in daylight hours. Our local diving capital. It was very well hidden. Depth 13m and water temperature was 26 degrees.
Regards
Sean Sequeira
westfax@netactive.co.za
Sequeira, S., 2002 (Jun 24) Halgerda toliara from South Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7323Dear Sean
This is a species of Halgerda. The network of ridges on its back are very distinctive. Your animal is probably Halgerda toliara which was recently described from Madagascar. Another possibility is H. formosa which normally has some black dots around the mantle edge. However it is possible that a juvenile, such as yours, may not a s yet have developed black spots.
Best wishes,
Bill Rudman
Halgerda toliara? from South Africa
June 30, 2000
From: Valda Fraser
Dear Bill
In other examples of Halgerda toliara I have photographed they all have a distinctive yellow line from between the rhinophores down to the gills. This fellow doesn't! Could this just be a variation?
Locality: Scottburgh - 25m - south coast KwaZulu-Natal, SOUTH AFRICA
Date: June 2000
Size: 25mm
Thanks.
Valda Fraser
iti04937@mweb.co.za
Fraser, V., 2000 (Jun 30) Halgerda toliara? from South Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2568Dear Valda,
Looking at Fahey & Gosliner's description of the original specimens from Madagascar, this animal fits exactly, including the small creamy pustules around the mantle edge and fine white line at the border [see inset]. There is an irregular yellow line down the middle of the back.
Externally Halgerda toliara is quite similar to Halgerda formosa which can sometimes have a distinctive yellow median ridge down the mantle, while at other times it is not so obvious. It usually has a few black spots on the mantle skirt. One other diference between the two is that in Halgerda formosa the black viscera can be seen through the dorsal body wall while in Halgerda toliara the visceral mass appears to be an opaque white mass.
I am pretty sure this photo falls within the normal variation of Halgerda toliara.
Best wishes,
Bill Rudman.
A good photo of Halgerda toliara
May 11, 2000
From: Valda Fraser
Dear Bill
The photo of Halgerda toliara which I sent you before was not very clear. Here is a better one.
Locality: Park Rynie - 25m, south coast KwaZulu-Natal SOUTH AFRICA
Date: May 2000
Size: 15mm
Regards
Valda
iti04937@mweb.co.za
Thanks Valda,
Bill Rudman.
Halgerda toliara from South Africa
November 17, 1999
From: Valda Fraser
Dear Bill,
Any idea with this one please?
Locality: South Coast of Kwa Zulu Natal, South Africa near Scottburgh. Rocky reef with prolific hard and soft coraline growth. Depth: 25-28m, March 1999, Size: 40mm
Valda Fraser.
iti04937@mweb.co.za
Fraser, V., 1999 (Nov 17) Halgerda toliara from South Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1528Dear Valda,
Shireen Fahey and Terry Gosliner have just published a paper on new species of Halgerda from the western Indian Ocean and I am pretty sure your animal is Halgerda toliara , a new species they describe from Madagascar.
They also discuss the identity of a very similarly coloured species, H. formosa, which Terry and I had both previously identified as H. punctata.
In brief the two species differ externally as follows:
H. formosa (Bergh, 1880) - yellow reticulate pattern - some black spotting around mantle skirt, and small whitish pustules near edge.
H. toliara Fahey & Gosliner, 1999. - yellow reticulate pattern - no black spots on mantle, small yellow pustules near edge.
On balance I think your animal is H. toliara, but if you have other photos or see the animal again you could look closely to see whether there are small yellow spots or pustules around the edge.
Best wishes,
Bill Rudman.
