Dear Kamal,
I am pretty sure the greenish colour is not 'real'. It's either something to do with the depth the animal was photographed at or more likely something to do with the 3 colour RGB format we use to display images. A slight imbalance in either the Cyan-Red or Magenta-Green scales can lead to a greenish tinge like this. I sometimes do a global rebalance of colours in images which are clearly in need of help, but usually don't interfere with images in case I get it wrong.
Best wishes,
Bill Rudman

Dear Matan,
This is a nice find. Although I am not a great believer in common names, 'Pyjama slugs' is certainly a nice way of labelling this colour group. This animal is almost certainly the same as the lower left photo in Ilan Ben Tov's earlier message [#9457] from the Red Sea. If colour patterns mean anything then I think I have to identify this asChromodoris kuiteri . Certainly Ilan's animal looked identical to eastern Australian specimens, and although the white lines in your animal are a bit irregular, it is the only species of this colour group in which there is black pigmentation on the inside edge of the orange mantle border.

Finding it on this red sponge is also exciting because it is almost certainly the same red sponge that C. quadricolor is usually found on. I have a record on the Forum [#1404] of this species feeding on Dysidea, but this could be wrong as it was based solely on the a photo that accompanied the specimen.

I could of course be quite wrong in thinking this is C. kuiteri, and this may be a strange colour form of C. quadricolor, but I suspect the best way to find out is for local observers like you, to keep an eye on these 'Pyjama slugs' and see if you can find some biological differences. It would be wonderful if you could find different colour 'forms' laying eggs - either the same or different, or mating etc etc. Perhaps you can notice a different shape of the body. For instance, in C. quadricolor and C hamiltoni, the mantle skirt down each side of the body is quite narrow compared to the relatively wide and thin skirt of C. africana. What we have here is almost certainly a case of mimicry, much like the red-spotted species I describe from southeastern Australia. This mimicry has evolved to survive predation, but although out brains are better than fishes, it is sometimes difficult, even for us, to separate one species from another on external colour patterns.

Best wishes,
Bill Rudman

Dear Gary,
As far as we know C. africana is a western Indian Ocean species althought ther are some puzzling animals from the Pacific which I am calling Chromodoris cf. africana at present for want of a better idea. Your animal however is Chromodoris kuiteri. The black pigmentation on the inside edge of the orange mantle border is a good character for this species
Best wishes
Bill Rudman

Thanks Julie,
It's nice to have a photos of another of these species which lay a flat egg coil. I have also included the blue sponge in the closeup as I wouldn't mind keeping an eye out for C. kuiteri eating this sponge.
Best wishes,
Bill Rudman

Dear Akos,
Yes this is a dark specimen of C. kuiteri.
Best wishes,
Bill Rudman.

Dear Nerida,
Yes, it's C. kuiteri. Similar in general appearance to Chromodoris magnifica, but one major difference is that in C. magnifica the inside edge of the orange border is adjacent to a white region, while in C.kuiteri there is a black band alongside the inner edge of the orange border.
Best wishes,
Bill Rudman.

Thanks for the information Nerida. I've put a copy on the Participant's Page. I suggest you get in touch with Wayne Ellis (glaskin@ozemail.com.au ), whose contact detail are on the Participant's Page. As I have said many times before if anyone has interesting photos of eggs, spawning, feeding etc, it would help us all if I could borrow and scan them so we could all have a look. ... Bill Rudman.

Dear Nerida,
I have records of it feeding on an unidentified species of the sponge Dysidea in southern Queensland and I assume it probably feeds on the same in northern New Spouth Wales. If you could let me know why you want to know it would be easier to help. Are you looking for the slug? or have you found it feeding on something and want to identify the food?

If you have found it commonly on a sponge I would very much like a photograph of it and the sponge, and a sample of the sponge. two days ago I was talking to Dr Pat Bergquist, a leading world expert on sponges who is at the moment wrapping up a revision of the genus in the tropics. If I can get some material for her it will possibly help her revision and help us identify another food sponge of a nudibranch.

Another person worth contacting would be Wayne Ellis (see his message below).

Reference: Rudman, W.B. (1984d) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: a review of the genera. Zoological Journal of the Linnean Society 81: 115-273.

Best wishes,
Bill Rudman

They are Chromodoris kuiteri. In a number of the chromodorids with this basic colour pattern, including Chromodoris westraliensis, Chromodoris elizabethina, Chromodoris magnifica the orange of the mantle border, gills and rhinophores seems to vary in different individuals from yellow to a deep orange. Since I first described this species nearly 20 years ago I know of no further records from Western Australia other than the single one from Houtman Abrolhos Ids that I recorded then. Since it is not uncommon in northern New South Wales and southern Queensland, it is possible that the Western Australian record is a mistake. Any sightings from outside northern NSW and southern Queensland would be valuable in determining its distribution.. Bill Rudman