UPPER: Phi Phi Islands, Thailand, divesite "Koh Bida Nok", depth 22m, size 49mm, 7 January 2001. Photo: Erwin Koehler.
LOWER: Drawing of preserved animal [Pl 3, fig 4] from Farran, 1905.
Farran (1905) described this species from a specimen collected in the Gulf Of Manaar, Ceylon [Sri Lanka]. Short colour notes accompanying the preserved specimen available to him described the colour as "pale whitish-gray, rather translucent with yellow papillae on mantle and purple spots on foot and few also on mantle".
He also described the shape of the preserved specimen as having "numerous large blunt tubercles arranged in more or less diagonal lines connected by ridges which form an irregular triangular network". I have scanned a copy of his original plate of the preserved specimen above. Such brief descriptions are always going to cause problems for later workers. I identified a specimen from Zanzibar with H. punctata, but it differed externally in having distinct ridges on the mantle (Rudman, 1978). This animal of Erwin's is a much better match with Farran's species in having a row of tubercles along the ridges. His use of 'purple' to describe the spots is to me not a problem. Often these dark blackish spots appear purplish or dark brown.
• Farran, G.P. (1905) Report on the opistobranchiate Mollusca collected by Professor Herdman, at Ceylon, in 1902. Report to the Government of Ceylon on the pearl oyster fisheries of the Gulf Of Manaar. Supplementary Report No. 21: 329-364. (Pls. 1-6).
• Rudman, W.B. (1978) The dorid opisthobranch genera Halgerda and Sclerodoris from the Indo-West Pacific. Zoological Journal of the Linnean Society, 62: 59-88.
Rudman, W.B., 2001 (February 21) Halgerda punctata Farran, 1905. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/halgpunc
May 14, 2007
From: Lars Dubies
I am happy, if you include my photo on the Forum.
I took it on 01 January 2007 on my first dive in Sri Lanka at "Hikkaduwa Gala" between 13-18 meter - and I see there a lot of slugs! [Hikkaduwa is in the southwest corner of Sri Lanka]
Matan Ninio told me about your photo so I am very glad to have it on the Forum. Halgerda punctata was described from Sri Lanka in 1905, from a preserved animal, so there has been considerable debate over its identity in recent years. The only photos I know of this species are the ones on the Forum of specimens from Burma, Thailand, and one from Sri Lanka. So your photo is valuable addition to our knowledge and is the first information we have on the shape and colour of the egg ribbon, and the size of the eggs. Best wishes,
March 11, 2005
From: Marina Poddubetskaia
I've seen you have few photos of Halgerda punctata on the Forum, so maybe you would be interested in these animals from Sri Lanka.
Locality: 'Cave', Hikkaduwa, Sri Lanka. Indian Ocean. Depth: 13 m. Length: Upper : 25mm. Lower: 20mm. 09 November 2004, rocks. Photos: Marina Poddubetskaia - Nembro website
email@example.comPoddubetskaia, M,, 2005 (Mar 11) Halgerda punctata from Sri Lanka. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13321
This is an exciting record. This species was first described from Sri Lanka so photos of living animals from there make a valuable addition to the photos we have from Burma and Thailand.
March 13, 2003
From: Sarah Heaney
Is this Halgerda punctata?
Data: Myanmmar [Burma]; divesite: Western Rocky. On a wall with lots of varying types of nudis. Dec 2002
firstname.lastname@example.orgHeaney, S., 2003 (Mar 13) Halgerda punctata from Burma. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9318
Yes this is identical to the other photos we have of this species by Erwin Koehler from Thailand. It is good to get more photos of this rarely discovered species as it will help us to get an idea on whether or not its colour pattern is variable. Certainly the only two photos we have at present don't show any variability.
February 23, 2001
From: Erwin Koehler
Here are some photos of another one from Thailand, Phi Phi Islands, divesite "Koh Bida Nok", depth 22m, size 49mm, 7 January 2001.
Shireen Fahey has identified it as Halgerda punctata Farran, 1905
Erwin@medslugs.deKoehler, E., 2001 (Feb 23) Halgerda punctata from Thailand. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3835
This is another interesting find. I agree with Shireen that from its external features it fits Farran's description of Halgerda punctata very well. I have discussed this in more detail at the top of the page.