Halgerda okinawa
Carlson & Hoff, 2000

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

DISTRIBUTION

Originally described from Okinawa, but records on the Forum from Indonesia suggest a wider distribution.

PHOTO

Seragaki, Okinawa (26o 30.4'N, 127o 52.6'E)
UPPER: Holotype. 86mm long., from 58m. LOWER: 105mm long. PHOTOS: Bob Bolland.

This recently described (Carlson & Hoff, 2000) species of Halgerda is relatively large, growing to at least 114mm long. It has the typical mantle ridges and depressions of most members of the genus. Apparently unique to this species, the yellow pigment on the tubercles is not just a surface pigment but is incorporated in the tissue right to the core of the tubercles. The species is also known from Indonesia (Gosliner et al, 1996 [p. 160 as Halgerda sp.] There is a page on Bob Bolland's Okinawa Site showing the holotype and paratypes of the species.

References:
• Carlson, C.H. & P.J. Hoff. (2000) Three new Pacific species of Halgerda (Opisthobranchia: Nudibranchia: Doridoidea). The Veliger 43(2):154-163.
• Fahey, S. J. & T. M. Gosliner. (1999) Preliminary Phylogeny of Halgerda (Nudibranchia: Halgerdidae) from the Tropical Indo-Pacific, with descriptions of three new species. Proceedings of the California Academy of Sciences 51(11): 425-448.
• Gosliner, T.M., D.W. Behrens & G.C. Williams. (1996). Coral Reef Animals of the Indo-Pacific. Sea Challengers, Monterey, California. vi + 314pp.

Authorship details
Rudman, W.B., 2000 (May 26) Halgerda okinawa Carlson & Hoff, 2000. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/halgokin

Related messages


Halgerda okinawa from Lembeh

October 29, 2009
From: Zeineb Alhaidari

Concerning message #16823:

Dear Bill,
Another wonder from Lembeh, these 2 Halgerda okinawa were observed on the dive site Makawide II. They were huge (the biggest about 15 cm) , and so beautiful! I have been told they are not common, so it could be of interest for the forum,

Locality: Dive site Makawide II , Lembeh strait, 16 metres, North Sulawesi , Indonesia, Molucca sea, 15 october 2009, Sandy bottom with scattered reefs. Length: 15 cm. Photographer: Zeineb Alhaidari.

Very best regards,
Zeineb Alhaidari

z.alhaidari@wanadoo.fr

Alhaidari, Z., 2009 (Oct 29) Halgerda okinawa from Lembeh. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22734

Thanks Zeineb,

We know little about some of these species so more photos are always useful. Although not present in all specimens, the black rings down each side of the mantle are very obvious in this animal.

Best wishes,
Bill Rudman

Rudman, W.B., 2009 (Oct 29). Comment on Halgerda okinawa from Lembeh by Zeineb Alhaidari. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22734

Halgerda okinawa from Indonesia

June 13, 2006
From: St├ęphane Sandon

Hello Bill,

This one was found in Alor last April. I browse your database and think it is like Halgerda okinawa. But it may differ slightly.

Locality: Kalabahi, Alor archipelago, 15 m, Indonesia, Banda sea, 28 April 2006. Length: 60 mm. Photographer: Stéphane Sandon.

Regards
Stéphane

stephane.sandon@wanadoo.fr

Sandon, S., 2006 (Jun 13) Halgerda okinawa from Indonesia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/16823

Dear Stéphane,
As you will see from the Fact Sheet, this species was only described in 2000, so we are still learning just how variable it is in colour. You will see from some messages that sometimes there are black rings around the mantle skirt, so your animal easily fits within the known colour variation of the species.
Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Jun 13). Comment on Halgerda okinawa from Indonesia by St├ęphane Sandon. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/16823

Halgerda okinawa from East Timor

March 10, 2006
From: Brian Francisco

Hi Bill

Here's an interesting Halgerda from East Timor which I found in my archive photos from 2004. Although I reviewed the species list to find a match, I'm not sure of the proper species name for this individual.

Locality: Remote Beach, 12 M, East Timor, Banda Sea, 18 December 2004, coral slope. Length: 4-5 cm. Photographer: Brian Francisco.

Brian

francisco.brian@gmail.com

Francisco, B., 2006 (Mar 10) Halgerda okinawa from East Timor. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15858

Dear Brian,
This is Halgerda okinawa. It is a species which has only recently been described so it's good to get more information on its colour variability and geographic distribution
Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Mar 10). Comment on Halgerda okinawa from East Timor by Brian Francisco. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15858

Halgerda okinawa from the Philippines

May 23, 2005
From: Erwin Koehler

Dear Bill,
scanning through all Halgerda shots in the web I find only Halgerda okinawa with yellow rhinophores. So, are these 3 specimens Halgerda okinawa or something else? In the field I thought it is a colour variant of Halgerda willeyi, at home I noticed the yellow rhinophores and gills.

Locality: Calangaman Island, Cebu north, Philippines. Depth: 22-32 m. Length: 7-9 cm. 05 May 2005. Photographer: Erwin Koehler

Regards Erwin
www.Philippine-Sea-Slugs.com

Erwin@Philippine-Sea-Slugs.com

Koehler, E., 2005 (May 23) Halgerda okinawa from the Philippines. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13815

Dear Erwin,
I would think these are all colour variations of Halgerda okinawa. Although there is quite a bit of variation in the yellow colouration on the ridges, the strong black lines radiating out from the tubercles, the yellow rhinophores, and the high gill pocket, all seem to charcterise the species.
Best wishes,
Bill Rudman

Rudman, W.B., 2005 (May 23). Comment on Halgerda okinawa from the Philippines by Erwin Koehler. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13815

Halgerda okinawa mating from Indonesia

January 7, 2004
From: Francis et Pirjo Pellet


Dear Bill,
Here is a nice "couple" from Indonesia. One of them was a really huge 111 mm. Are these Halgerda okinawa or is it better to consider them as Halgerda sp ?

Indonesia, Lembeh straits
dive site "Aw Shucks"
length: 111 mm
depth: 25 m
26 September 2003

Thanks
Francis & Pirjo Pellet

pirjo.pellet@free.fr

Pellet, F. & P., 2004 (Jan 7) Halgerda okinawa mating from Indonesia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/11557

Dear Francis & Pirjo,
I am sure your identification is quite correct. We know very little about this species except for a few records from Okinawa and Carine Schrurs & Constantinos Petrinos' photo from Lembeh Straits, Indonesia [see Dave Behrens' report]. Your photo is a very useful confirmation as their specimen lacked the black lines which usually run up each tubercle, and which are clearly present in your animals. Another interesting addition to our knowledge is that there can be a yellow-orange line along the gills as well as the scattered black spots.

Anohter point of interest are the little patches of orange sponge which could possibly be the food preference of this species
Best wishes
Bill Rudman

Rudman, W.B., 2004 (Jan 7). Comment on Halgerda okinawa mating from Indonesia by Francis et Pirjo Pellet. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/11557

Halgerda okinawa from Lembeh Straits

March 2, 2003
From: Dave Behrens


Bill,
Have wanted to correct the range on Halgerda okinawa but didn't have photo documentation to back up the claim. H. okinawa is a casual occurrence in the Lembeh Straits of Indonesia in addition to the type locality in Okinawa. The attached photographs are by Carine Schrurs and Constantinos Petrinos. Con reports - During a dive at a dive site called NUDI RETREAT we located several Halgerda okinawa within an area of 10 meters at a depth of 42.5 meters.
My best,
Dave Behrens
Sea Challengers

info@seachallengers.com

Behrens, D., 2003 (Mar 2) Halgerda okinawa from Lembeh Straits. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9322

Thanks Dave,
These animals certainly match the colour of the Okinawan specimens except for the absence of the black lines on the ridges. The broken black rings near the mantle edge, which are so well developed in this Indonesian animal, seem to definitely link it to the Okinawan animals, one of which shows markings which could easily be derived from these rings. This is an interesting find.
Cheers,
Bill Rudman

Rudman, W.B., 2003 (Mar 2). Comment on Halgerda okinawa from Lembeh Straits by Dave Behrens. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9322

Halgerda okinawa

June 11, 2000
From: Bill Rudman.

With Bob Bolland's help, I have added a page on Halgerda okinawa.

Best wishes,
Bill Rudman.

Rudman, W.B., 2000 (Jun 11) Halgerda okinawa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2556