(Gosliner & Willan, 1991)
Probably widespread in Indo-West Pacific
Kwajalein Atoll, Marshall Islands. PHOTO: Scott Johnson. See further photos below
• Gosliner,T.M. & Willan,R.C. (1991) Review of the Flabellinidae (Nudibranchia: Aeolidacea) from the tropical Indo-Pacific, with the descriptions of five new species. The Veliger, 34(2): 97-133.
Rudman, W.B., 1999 (July 1) Flabellina bilas (Gosliner & Willan, 1991). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/flabbila
June 15, 2007
From: Wendy Atkinson
Which Flabellina could this be? Sorry about the terrible head shot...
Locality: Raja Ampat Islands, West Papua, Indonesia. Photographer: Wendy Atkinson.
firstname.lastname@example.orgAtkinson, M.W., 2007 (Jun 15) Flabellina bilas from Raja Ampat. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19318
June 24, 2003
From: Harro H. Quitzau
I found this Flabellina bilas at my last trip to the Red Sea.
Egypt, Safaga - Shaab Hamdalla
31 May 2003 - 22,5m - Size 3cm
Harro@Quitzau.infoQuitzau, H, 2003 (Jun 24) Flabellina bilas from the Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/10243
After Lindsay Warren's record of an animal from Madagascar, I predicted this species was probably widespread throughout the Indo-West Pacific so your record from the Red Sea pretty much allows us to say it is widespread throughout the Indian Ocean and so confirms its wide distribution.
February 22, 2002
From: Lindsey Warren
Another specimen found during my recent trip to Madagascar. I found this Flabellina bilas on 22 January 2002 at about 1pm while diving on La Baleine rocks in the Iles Mitsio, NW Madagascar. It was crawling on rubble at a depth of 63 ft. L: 40 mm. Photo: Lindsay Warren.
Am I right in thinking that the red 'vein' leading into the cerata is part of the digestive system? If so, what is the orange mass which runs most of the length of the body? If part of the digestive system, why the difference in colour? Incidentally I have close-ups of the head and cerata should you want them for the Forum.
Looking forward to your comments.
All the best
email@example.comWarren, L., 2002 (Feb 22) Flabellina bilas from Madagascar. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6224
Thanks for this photo. Yes the reddish dict is the digestive gland duct which runs up the centre of each cerata. The orange mass, which is not clear in the photo, will be the lobes of the ovotestis. In most aeolids the digestive gland is restricted to the cerata. Exceptions are Protoaeolidia atra which has a large section of the digestive gland within the body cavity, and those aeolids with symbiotic zooxanthellae. In these animals there is a fine network of ducts throughout the body wall to accomodate the symbiotic plants.
Concerning other photos. I would be happy to look at them - if they show interesting details of the head, rhinophores and cerata, they would be very welcome. This find is quite a major range extension for the species. It was described from Marshall Ids and Papua New Guinea and I don't know of other records further afield. Your record is certainly the first from the western Indian Ocean which would suggest that the species is probably widespread throughout the Indo-West Pacific.
June 28, 2000
From: Scott Johnson
Looking over some of last year's messages, I noticed your request for photos of Flabellina bilas. Here are shots of two different individuals from Kwajalein in the Marshall Islands. Both were in the 45-55mm range.
Johnson, S., 2000 (Jun 28) Photos of Flabellina bilas. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2626
Thanks for your photos. I am particularly pleased with the UPPER photo which clearly shows the paddle-shaped oral tentacles. I have seen these in specimens of Flabellina bicolor and in a photo of F. bilas in Gosliner & Willan's paper. However no one seems to have commented on it. To see them sofly 'banging' their paddles down on the substrate as they crawl along is a quite remarkable sight. I don't understand its function and I have seen animals with apparently normal oral tentacles, so I can't even guess what's going on.
If you, or anyone else, has noticed this behaviour in any Flabellina I would be interested in hearng about it.
June 29, 1999
From: Grey McNeil
Could you identify this photo please. The details are:
RASCHS REEF, MADANG, Papua New Guinea, 2cm long, 5m Jan 1999.
GREYMACIND@bigpond.comMcNeil, G., 1999 (Jun 29) Flabellina bilas. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/992
I think this is Flabellina bilas which is similar in shape to Flabellina bicolor but has a red ring on the upper half of each ceras with a white band above and below it. Unfortunately I don't have a good photo of this species to put on the Forum but hopefully someone will help us out.
Bill Rudman.Rudman, W.B., 1999 (Jun 29). Comment on Flabellina bilas by Grey McNeil. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/992