See Hexabranchus sanguineus Page 1 for background information and other messages.Authorship details
Rudman, W.B., 2001 (August 27) Hexabranchus sanguineus Page 2. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/hexasang2
March 26, 2010
From: Franco De Lorenzi
Dear prof. Rudman in my archive I have this Doridae taken in Bunaken. The trasparent notum may represent a juvenile phase.
All that I can say is that I found it in between a zone of coral ending on sand. As always I hope you can help me to know more about it.
Locality: Bunaken - Alban - Night dive, 12 metres, Indonesia, indopacific ocean, 21 august 2007, sand, coral . Length: 13 mm. Photographer: Franco De Lorenzi.
Thanks a lot
firstname.lastname@example.orgFranco De Lorenzi, 2010 (Mar 26) Chromodoris or Hypselodoris?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/23392
I first encountered this little animal when I was revising the Indo-West Pacific species of Hypselodoris and Chromodoris and was pretty sure it was a Chromodoris and had placed it with a group of similarly coloured species [see C. decora colour group Fact Sheet] which I was planning to dissect as a group. Howevere I was greatly surprised when I dissected it to find its radular teeth were quite different from a chromodorids and its anatomy showed it was a juvenile Hexabranchus sanguineus.
If you look through some of the messages we have of this species on the Forum you will see stages showing its chnage form this colour pattern to the brilliant red and white of the adult Spanish Dancer.
February 23, 2010
From: Sean Houlihan
I found this guy washed up on a beach in north-western Australia near Dampier years ago but I have never been able to pin it down to a genus. Can you help?
Locality: Dampier, Western Australia, June 2004. Length: 6-8 inches
email@example.comHoulihan, S.M., 2010 (Feb 23) Washed up in north-western Australia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/23266
Nice to get an easy one now and again. Although it looks a bit sad washed up, this is the spectacular Hexabranchus sanguineus commonly known as the Spanish Dancer, because as it swims by flapping its wide colourful mantle skirt, it is reminiscence of a flamenco dancer.
In the close-up alongside which shows the circlet of gills you will see there are six which is why it was named Hexabranchus [hexa = six; branchus = gill]. The name sanguineus [= bloody] is not a reference to the great Australian adjective but to the red splashes all over the mantle skirt. Have a look at the two pages of messages on this species [Page 1, Page 2] for more information.
September 25, 2009
From: Gary Cobb
Concerning message #8417:
Hi Bill and everyone!
During our two dives at Shellacey Reef off Mooloolaba in Queensland, I ran across 3 baby Hexabranchus sanguineus. The average size was about 15-25 mm.
In these photos you can see the 6 gill sections and the rolled margins.
Locality: Shellacey Reef, Mooloolaba, 15 m depth, Queensland, Australia, Pacific, 12 September 2009, Subtidal. Length: 15-25 mm. Photographer: Gary Cobb.
Cobb, G, 2009 (Sep 25) Hexabranchus sanguineus from sthn Queensland. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22662
At this size they certainly look like a different species.
May 8, 2009
From: Sully Bachel
Concerning message #14907:
I have some problems with the identification of this nudibranch. I'm quite sure that is not a Hypselodoris maculosa.
Perhaps it is Thorunna australis: one longitudinal white line on the mantle, a reddish band on the rhinophores
Locality: Cap La Houssaye St Paul, 10 m, Reunion Island, Indian Ocean, 23 August 2008. Length: 15 mm. Photographer: Sully Bachel.
What is your opinion
firstname.lastname@example.orgBachel, S., 2009 (May 8) Juvenile Hexabranchus sanguineus from Reunion Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22431
This colourful little animal immediately makes you think that you have found a nice chromodorid, but it is in fact a juvenile Hexabranchus sanguineus. There is no easy way to distinguish it externally as a Hexabranchus at this small size because the characteristic oral lobes and separate gills are not clear at this early stage of its growth. When I was reviewing chromodorids with this colour pattern I thought I had a new species until I had a look at its anatomy and realised my mistake.
February 11, 2008
From: Chris Ryu
Can you give us the scientific name of this species. We have been researching to do a science report. I think we narrowed it down to some type of Nudibranch (?). Can you give us a clue where we can find more info on Structural and Behavioural Adapations as well? .
Locality: Wialea, , Shoreline, Maui, Hawaii, Pacific Ocean, 21 August 2006, intertidal. Length: 5 -6 inches. Photographer: Chris Ryu.
email@example.comRyu, C., 2008 (Feb 11) Hexabranchus sanguineus from Maui, Hawaii. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21297
This is Hexabranchus sanguineus. It is often found swimming and the ways it swirls it mantle skirt when swimming has given it the common name of the Spanish Dancer. Have a look at the Fact Sheet [and page 2] and the messages attached to those pages for more information
December 5, 2007
From: David Mullins
I notice that the forum has 2 pages of information on Hexabranchus sanguineus, but how much is enough?
Locality: Old Woman Island (Mudjimba Is.), Maroochydore,, 14 metres, Queensland, Australia, Pacific Ocean, 9 June 2007, Rocky reef. Length: 140 mm. Photographer: David Mullins.
The following pics show a specimen of Hexabranchus sanguineus hosting 2 very different species of "commensal" shrimp on its mantle and gills and appears in no way irritated by their presence. The crustacean on the gills [middle photo] appears to be a type of hinge-beak or perhaps humpback shrimp which I have not seen before.
I believe the shrimp on the mantle is Periclimenes imperator which is well known in this role on Dorids. It has managed to affect the colour and stippling of its slug host upon its body,one of its 2nd chelipeds and even the eye stalks.
My patience in focusing on the gills [lower photo] was "rewarded" quite unexpectedly with this scatological moment. Perhaps it was this close and constant attention that induced "the deed". Some observers have reported that the shrimp feed upon these fecal pellets and what appears to be remnants of one can be seen around the tail and anterior end of P. imperator.
firstname.lastname@example.orgMullins, D.A., 2007 (Dec 5) The secret life on Hexabranchus sanguineus. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21256
I haven't felt the need yet to say 'no more' for any species.
I am surprised at how few photos we have on the Forum of Periclimenes on Hexabranchus but if you do a search for Periclimenes on the Forum you will find lots of photos of it associated with other opisthobranchs. I am pretty sure the shrimp on the gills is a juvenile of Periclimenes imperator. The white-spotted colour form of your larger animal is not the usual colour form of this species which usually has a white band down the back and a wider white collar just behind the 'head' [see photo on Symbiosis Fact Sheet]. The white spots are usually present on the posterior end of the body. If you look carefully at the gill-dwelling animal you can see a faint whitish collar behind the head.
Faecal pellets can be a useful indicator of food specificity, and from the orange bits I can see in your photo I suspect it has been eating an orange sponge. JUst knowing the colour of its food is not enough but if you found an animal producing faecal pellets with orange bits and it was sitting on an orange sponge, or surrounded by an orange sponge it would be a valuable clue. In sponges that have siliceous spicules, finding large numbers of thsoe spicules in the faecal pellets is also a valuable clue, but sponge spicules are scattered all over the sea bottom, so finding an identifying a few sponge spicules from an slug's stomach may be misleading and just indicate that they don't wash their food before eating it.
September 17, 2007
From: Edward Dixon
Hello again sir.
Back from Wakatobi where, while diving at about 65 feet on either Lorenzo's Delight or Spiral Corner (TBC), I found this massive Spanish Dancer on the back wall of an undercut during a day dive. I was amazed at its size. I believed it to be over 2 feet long, and called my dive buddy Seth down to put his hand in as a reference. Was using a 60 macro and the dancer was at least 3-5 feed deep in the undercut, so Seth's hand is probably 10-12 inches from the body. When we came up, Wendy the guide said it might have been one of the Djibouti Giants ... I tried to take various shots of the rhinopores, gills, etc. but it was challenging because it was so deep in the undercut. Beautiful and awe-inspiring whatever it was...got a lot of high-fives on the boat after the dive.
Locality: Wakatobi, 65 feet, South Sulawesi, Indonesia, Banda Sea, 02 September 2007, Lorenzo's Delight or Spirial Corner (Walls). Length: minimum 24 inches. Photographer: EFDixon.
Lots of beautiful slugs and flatworms there... see http://www.flickr.com/photos/efdixon/sets/72157601877715362/ for more from my trip.
email@example.comDixon, E.F., 2007 (Sep 17) Hexabranchus sanguineus or Djibouti Giant?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20682
Its definitely Hexabranchus sanguineus. It seems in some places this species has a reputation for growing rather large. I comment on the large ones [about 2 feet long] from Djibouti in an earlier message which reports large animals from Fiji [#2965] - another place where 'giants' have been found quite often.
August 24, 2007
From: Natasja Vandeperre
Is this Hexabranchus sanguineus feeding?
Locality: Tofo, Mozambique, Indian Ocean, 22 July 2007. Photographer: Natasja Vandeperre.
firstname.lastname@example.orgVandeperre, N., 2007 (Aug 24) Feeding Hexabranchus sanguineus from Tofo, Mozambique. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20510
Yes it certainly seems to be feeding on a reddish sponge. Hexabranchus is reported to feed on quite a few different species of sponges [see references page], but we still have much to learn of its biology and natural history
August 16, 2007
From: Diane Hennelly
Concerning message #1985:
There is video of Hexabranchus sanguineus dancing at:
email@example.comHennelly, D., 2007 (Aug 16) Re: Hexabranchus sanguineus video. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20487
The message you are referring to was posted in 2000 - I hope Marco found a video before now.
August 11, 2007
From: Natasja Vandeperre
Locality: Tofo, Mozambique, Indian Ocean, 16 July 2007. Photographer: Natasja Vandeperre.
Vandeperre, N., 2007 (Aug 11) Hexabranchus sanguineus from Mozambique . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20413
I am not sure if there is an abnormality or not. Hexabranchus is unusual in that every gill is attached separately to the body wall, not into a common trunk or vessel as occurs in most dorids. The name Hexabranchus comes from the Greek words for six gills and it is usual to have six, sometimes seven, separate gills arranged in a circle around the anus. In this animal a couple of the gills seem to be missing and I can't see the anus. It could be some developental abnormality or damage that has repaired itself - I can't say.
I have included a close-up of the head region because its shows another peculiarity of Hexabranchus - the strange hand-like [palmate ] lobes on either side of the mouth which replace the normal oral tentacles. These lobes have a series of fingerlike papillae around the edge which no doubt have a sensory function. There is considerable debate about the significance of these lobes, and the gill structure, in understanding just which dorids Hexabranchus is most related to.
August 11, 2007
From: Natasja Vandeperre
On my trip to Tofo, Mozambique I met a lot of Hexabranchus sanguineus. They were all orange from color. Unlike the Red Sea, I saw them during daytime. Most of them I saw at Manta Reef.
This one was laying her eggs.
Locality: Manta Reef, Tofo, 20m, Mozambique, Indian Ocean, 11 July 2007. Length: 200mm. Photographer: Natasja Vandeperre.
firstname.lastname@example.orgVandeperre, N., 2007 (Aug 11) Hexabranchus sanguineus from Mozambique . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20409
These orange-red animals certainly show how appropriate the scientific name is [ sanguineus = bloody] - mind you, that's excluding the Australian use of the word of course.
July 11, 2007
From: Donald Miles
This fantastic spanish dancer was found at Long Reef Marine Reserve in a large tidal rock pool. could you please let us know the scientific name for this particular specimen.
Locality: Long Reef, rock platform, Collaroy, Sydney, NSW, Australia, Pacific Ocean, 30 March 2007, Tidal rock pool. Length: 200 mm. Photographer: Don Miles.
email@example.comMiles. D.W., 2007 (Jul 11) Spanish Dancer from Sydney. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20185
If you are looking for something on the Forum like a scientific name its always worth using the Forum search box on top left of every page. I dont encourage common names but the Spanish Dancer is one that is definitely in common use. It scientific name is Hexabranchus sanguineus [hexa = six; branchus = gills; sanguineus = blood red].
I am glad you didn't find the scientific name yourself because I migth never have found out you had found this species in Sydney. I know I often tell people you have to expect to find tropical species in Sydney every now and then but I must say this is the first time I have heard of this icon of tropical waters being found this far down the New South Wales coast.
For thos of you who don't know Long Reef, it is a rocky reef jutting out at right angles from the shore like an arm outstretched to catch larvae washing past. I remember seeing a list of the tropical cowries in the Australian Museum collections from Long Reef, and if you didn't know where it was you would have been sure, from the number of species on the list, that Long Reef must be in the middle of the Great Barrier Reef, rather than the temperate waters of central New South Wales. But the list was an accumulation of finds over 100 years not from a day or a week. Be that as it may, I still find it amazing that Sydney has played host to a Spanish Dancer for sufficient time for it to grow to 200 mm.
May 4, 2007
From: Jen Jenny
Concerning message #19636:
The photographer is Ben Stobart. He is a professional photographer from Majorca, Spain.
I'm sure he will be pleased to get an identification. I am forwarding him your response. Thanks so much!
firstname.lastname@example.orgJenny, J., 2007 (May 4) Re: Nudibranch from the Seychelles, Indian Ocean. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19857
I've added his name to the original message.
April 27, 2007
From: Jen Jenny
I have been forwarded this picture, and asked for help with identification. I'm stumped. The photo was taken at approximately 30m depth, somewhere near Astove. Any identification ideas?
Locality: Astove Atoll, 33m, Seychelles, Indian Ocean, Shell/Sand. [Photo: Dr. Ben Stobart, Aldabra Marine Programme, (www.aldabra.org )]
email@example.comJenny, J., 2007 (Apr 27) Nudibranch from the Seychelles, Indian Ocean. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19636
Can you please let me know the name of the photographer so I can add it to the message please.
This is a form of Hexabranchus sanguineus. Have a look at the Fact Sheet and associated messages for further information. From the size of the hand in the photo this is obviously one of the 'giants' which are sometimes reported from various parts of the Indian and Pacific oceans.
April 13, 2007
From: Asther Lau
Concerning message #17274:
Here's a photo of a Spanish Dancer found during our sunset dive in Tulamben, Bali.
Locality: Coral Garden, Tulamben, 10 metres, Bali, Indonesia, Java Sea, 07 July 2006, Broken coral reef. Length: Approximate 18cm. Photographer: Asther M. Lau.
firstname.lastname@example.orgLau, A, 2007 (Apr 13) Hexabranchus sanguineus from Bali. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19813
One interesting feature of Hexabranchus is that instead of having a single oral tentacles on either side of the mouth it has a flattened hand-like lobe. In your photo you can see the 'fingers' of the left lobe poking out from under the mantle skirt
December 4, 2006
From: Sandrine Flodrops
What a strange place for sleeping and perhaps eating. I found this Hexabranchus sanguineus at the setting sun. We know that H. sanguineus is potentially toxic because it eats antifeedant chemicals found in Halichondria sponge.
Locality: Etang-Salé Lagoon, 50 cm, Reunion Island, Indian Ocean, 27 November 2006, Setting sun. Length: 130 mm. Photographer: Sandrine Flodrops.
Here is what I think is a kind of Millepora. Is it possible that H. sanguineus eats Millepora and also Ophiocoma?
Thanks for your comments.
email@example.comFlodrops, S., 2006 (Dec 4) Hexabranchus behaviour. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/18683
I know of no evidence that it feeds on either the anthozoan coral, Millepora, or brittlestars like Ophiocoma. Certainly Ophiocoma lives entangled in branching corals and coral rubble and is usually only seen in numbers like this when it crawls up to the water surface as the tide turns, to collect the dried organic particles and 'scum' it eats from the water surface. Hexabranchus is often found in coral rubble and areas of small branching coral colonies. Like many dorids, it is able to nestle into very small and inconvenient cracks and crevices when it is not actively crawling or feeding.
I suspect there is nothing significant about finding these three animals together.
November 8, 2006
From: Roxanne Fea
We also found these two species in Hugo's Trench at Julian Rocks last week and are unable to ID them. Do you have any suggestions?
Locality: Hugo's Trench, Julian Rocks, 10m, NSW, Tasman, 22 August 2006, Sheer walls. Length: Nudi: 30mm, Other: 20mm. Photographer: Roxanne Fea.
Looking forward to your response;
Roxanne Fea & Jason Coombs
firstname.lastname@example.orgFea, R.I., 2006 (Nov 8) Juvenile Hexabranchus from nthn New South Wales. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17652
This animal is a juvenile, or at least subadult, Hexabranchus sanguineus. When they are small they are often mistaken for a species of Chromodoris. It's a bit hard to see but one way small Hexabranchus can be identified is the way the gills are each attached individually to the mantle, and there is no real gill pocket into which they can retract.
I have moved one of the species you mention into a separate message. Can you please remember to include only one species in a message - unless of course it is a message about multiple species.
September 1, 2006
From: Kamal El Tawil
Concerning message #17493:
We all know that spanish dancers swim, but I was wondering if they had the ability to lift-off on their own and swim. Sadly, on the few times I've seen them swimming it was because some diver lifted and released them in midwater.
email@example.comEl Tawil, K., 2006 (Sep 1) Re: Dancing 'Spanish Dancer'. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17672
Although you are correct in observing that swimming in Hexabranchus is often initiated by humans, that is not always the case. I have certainly found swimming animals in deserted places where there are no signs of other people around, and I have also seem animals crawling along and spontaneously beginning to swim. The behaviour of quickly opening their folded over mantle to show their brilliant red and white colours, and their swimming, is considered to be a defence mechanism.
August 25, 2006
From: Joseph De Vroe
I was lucky to see this beautiful creature 'dancing' at the beginning of a nightdive at Poseidon Garden, Red Sea..
Locality: Poseidon Garden (Shaab El Erg), 8m, El Gouna, Egypt, Red Sea, 19 July 2006, sandy. Length: 25cm. Photographer: Joe De Vroe.
firstname.lastname@example.orgDe Vroe, Joe, 2006 (Aug 25) Dancing 'Spanish Dancer'. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17493
This bright red variety seems to be quite common in the Red Sea. It is indeed a spectacular sight when it is swimming
August 7, 2006
From: Kevin Lee
You recent message to Molly [#17128], prompted me to look more closely at the Spanish Dancer, which I saw for the first time in Bali, Indonesia a few weeks ago. The juvenile form & color are amazing. I, for one, appreciate the rich archive of data available on SSF. Here are a few photos of the "dancer".
Locality: Ahmed, 35fsw, Bali, Indoneisa, Java Sea, 06 June 2006, Sandy bottom. Length: Approx. 10 inches (all 3 separate individuals). Photographer: Kevin Lee.
Lee, K., 2006 (Aug 7) Hexabranchus sanguineus from Indonesia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17274
Thanks for these photos. Spanish Dancer is one of the few 'common names' which are truly common names in the sense of being commonly used world-wide - at least by English speakers. Yoir photo alongside of a swimming animal shows just how appropriate this name is.
The yellow animal shows the strange hand-like oral tentacles found in this species, and I am pretty sure I can see a commensal shrimp on the right side of the animal just behind the right rhinophore [left side in photo]. The other close-up shows a much enlarged view of one of these shrimps - Periclimenes imperator - which are found living on a variety of large sea slugs
July 29, 2006
From: Molly Ogden
Concerning message #9752:
Hello, Its Molly Ogden again, Its been three years since I wrote that message, so could you please take it off the internet?
email@example.comOgden M., 2006 (Jul 29) Re: Spanish Dancer Research Paper. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17128
The purpose of the Forum is to build up a store of information on sea slugs by keeping the contributions people make so it is available for future use. This means that the Fact Sheets are only a starting point for information. For example, if you want to know about the Spanish Dancer you don't just look at the Fact Sheet, you also look through the messages that have accumulated on that species. If you are lucky, someone will have already asked the question you are interested in, and received a useful answer. People's views on a topic, and identifications, may change over time, so the Forum is also an historical record of changing views and ideas.
More importantly, a lot of time has been spent by me and others providing observations and answers. These answers were not just for the person who asked the question, but for anyone who would like to know. If I remove them, I might as well have sent you a private email, which negates the whole value of the world wide web to share and disseminate information. Your 3 year old message is still on the Forum, not because I haven't got around to getting rid of 'out of date' messages, but because I don't plan to delete them. The Forum is not part of our 'throw away society' - all messages on the Forum are valuable, no matter how old they are.
March 3, 2006
From: Brian Francisco
Is it possible that these photos are of a juvenille Spanish Dancer [Hexabranchus sanguineus]. This individual was quite small, about 12 mm, and I'm not sure I can count 6 gills.
Locality: Beach, 7 meters, East Timor, Banda Sea, 26 February 2006, Sandy Bottom. Length: 12mm. Photographer: Brian Francisco.
Thanks very much
firstname.lastname@example.orgFrancisco, B., 2006 (Mar 3) Could this be a Spanish Dancer?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/16000
Yes this is indeed a juvenile Hexabranchus. Good call! The gills in juveniles are quite interesting. The dorid nudibranchs are divided into two large groups depending on whether their gills can retract into a protective pocket [Cryptobranchia or Eudoridoidea] or do not have such a pocket [Phanerobranchia or Anadoridoidea]. Obviously in adults, Hexabranchus has no sign of a gill pocket and each gill is separately inserted into the skin. It would seem to be clearly a phanerobranch. However phanerobranchs are usually the elongate forms, such as the nembrothids, while the large flat dorids with wide mantle skirts are usually cryptobranchs, with a gill pocket. Cryptobranchs are also sponge feeders, like Hexabranchus, while the phanerobranchs are all specialised feeders on a wide variety of invertebrates. There are of course other anatomical differences.
However if you look at juvenile Hexabranchus, you can see there seems to be a ridge around the gills and the tissue inside that is translucent, without the colour pattern of the rest of the mantle. I wouldn't be surprised if that is all that is left of a gill pocket, which has been lost in the evolution.of this species, but is still indicated in juveniles. Does that make Hexabranchus a very special cryptobranch, or does it suggests that it is a link between the two groups, indicating that the phanerobranchs evolved from the cryptobranchs? I wouldn't like to say.at this stage, but it is certainly something that students of phylogeny should consider. I'm glad you picture shows it so clearly. In living animals they gills can almost completely disappear.
November 8, 2005
From: Joseph De Vroe
What was my surprise when I found during a day-dive two kissing Spanish Dancers! [Hexabranchus sanguineus ] Is this a normal behaviour ?
Locality: Blind Reef, Egypt. Red Sea. Depth: 26 m. Length: both were ± 30 cm. 31 July 2005. stony. Photographer: Joe De Vroe
Thanks in advance for your comments,
email@example.comDe Vroe, J., 2005 (Nov 8) Kissing Hexabranchus sanguineus. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15168
Sorry to be a spoilsport, but as far as I know, 'kissing' has never been considered a behaviour that sea slugs engage in. Not being able to see, one of the main ways slugs can make sense of their surroundings is through touch. Often when two animals meet head to head like this they will nudge around, no doubt searching for the right 'smells' on the other animal. If all is well, they then have to respond by moving down the right side of their partner's body so that their mating organs are aligned.
November 4, 2005
From: Joseph De Vroe
Enclosed a picture of a Spanish Dancer (Hexabranchus sanguineus ) with only one gill !
Locality: Gotta Shaab El Erg, Egypt. Red Sea. Depth: 8 m. Length: 20 cm. 28 July 2005. Photographer: Joe de Vroe
firstname.lastname@example.orgDe Vroe, J., 2005 (Nov 4) Hexabranchus sanguineus with one gill. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15167
Since 'Hexabranchus' means 'six gills', perhaps we should call this Monobranchus. I can't say whether this is a development problem or predator damage. I'll add it to the abnormalities page.
An earlier message from Erwin Koehler [#2964 ] of an animal from the Gulf of Aqaba, with 4 gills, suggests that something may have a liking for these gills. In both animals there seems to be a 'stump' where each gill should be.
September 21, 2005
From: R. Grooters & M. Snoek
Here we have two pictures from mating Hexabranchus sanguineus, one of which is quite excited showing the red dots. If you zoom in it seems that there a two 'tubes' visible. Can you explain why?
Locality: Manta Reef, Tofo, Mozambique, Indian Ocean. Depth: 15 metres.
Length: about 15 cm each. 23 November 2004. rocky reef. Photographer: Reindert Grooters
Reindert Grooters & Mieke Snoek
Grooters, R. & Snoek, M., 2005 (Sep 21) Mating Hexabranchus sanguineus. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14788
Dear Reindert & Mieke,
It is interesting to see this plain orange colour form which I also found in Tanzania, just north of Madagascar. It is hard to be sure if there are two tubes there, but if there are it's what you would expect, as these animals are hermaphrodite, each animal having a fully functional male and female reproductive systems. Sometimes they mate as either a male or a female, but usually mating is reciprocal, so sperm is exchanged during matings by both partners. If there are two tubes here, they will be part of the male reproductive apparatus, each partner inserting its penis into the vaginal opening of the other.
September 3, 2005
From: Colin Ogden
Those previous Hexabranchus really fooled me [message #14676 ]. Here are some other juveniles, which I took on the same reef. At least I don't think these ones have confused me.
Locality: Sodwana Bay, South Africa. Indian Ocean coast. Depth: 22 metres
Length: 30 mm. July & Aug 05 2005. Coral reef. Photographer: Colin Ogden
email@example.comOgden C M, 2005 (Sep 3) Re: Juvenile Hexabranchus. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14701
These are quite interesting as they show a gradation from your previous juveniles to more obvious Hexabranchus. You can see reddish spots and blusih white bands of the juveniles but the folded mantle edge and submarginal reddish orange band of the adults.
September 2, 2005
From: Colin Ogden
I got these 2 photos almost a month apart.
The upper one was on August 2nd and was approx 20mm.
The lower photo was today August 30, and was less than 10mm.
Locality: Sodwana Bay, Bikini Reef, South Africa. Indian Ocean coast. Depth: 22 metres. Length: 20 mm. 30 August 2005. Coral reef. Photographer: Colin Ogden
I believe them to be Hypselodoris rudmani. Is my ID correct. There does not appear to be any change as this nudi matures.
firstname.lastname@example.orgOgden C M, 2005 (Sep 2) Juvenile Hexabranchus strikes again. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14676
I wish it was H. rudmani - I haven't seen many photos of my namesake. However these are juvenile Hexabranchus sanguineus, an animal that fools the best of us. When I was doing a review of all the little red and purple spotted chromodorids I was sure this was a chromodorid until I looked at its anatomy. The only external clue are the gills don't have a real pocket to retreat into. See Robert Sozzani's photo [#9954].
July 11, 2005
From: Kamal El Tawil
Concerning your comment [message #14083 ]
I absolutely agree with you. I havent seen any Hexabranchus anywhere near the egg ribbon.
Ktawil@yahoo.comEl Tawil, K., 2005 (Jul 11) Re: Hexabranchus sanguineus from Egypt. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14200
July 4, 2005
From: Marco Angelozzi
Can you please tell me what species is this??
Locality: Nosy Iranja, Madagascar. Length: about 300 mm. June 2005.
Photographer: Marco Angelozzi
email@example.comAngelozzi, M., 2005 (Jul 4) Hexabranchus sanguineus from Madagascar. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14178
You were right when you gave the photo the file name 'ballerina_spagnola'. It is indeed the Spanish Dancer, or Hexabranchus sanguineus. As we can see in your photo, when the animal is crawling or 'resting' the edges of the mantle fold over and hide the bright red and white colour pattern. However when it is startled or disturbed, the mantle rolls open to display the bright colour pattern, and swimming is sometimes initiated. We think this is a 'startle display' to frighten predators. See the Fact Sheet on colour patterns for more information.
June 24, 2005
From: Kamal El Tawil
Thanks for posting my pictures on your site and also for your comments and valuable information [message #13977 ].
Ss for the egg ribbon, I always thought that the one in my picture was that of Hexabranchus sanguineus. Perhaps I am now mistaken ? Do other species have similar egg ribbons ?
Kamal el Tawil
firstname.lastname@example.orgEl Tawil, K., 2005 (Jun 24) Re: Hexabranchus sanguineus from Egypt. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14083
I am not saying that you are mistaken. Your egg ribbon is probably that of Hexabranchus, but it is possible that another big dorid nudibranch may have laid the egg ribbon. I need to be sure that the 'facts' on the Forum are backed by evidence. Egg ribbons are a good example. An animal may lay an egg ribbon then crawl away. The another animal of a completely different species may crawl up to it just as a photographer swims by. If we assume that the closest animal to an egg ribbon is the 'mother' we will make many mistakes. That's why I asked.
You are probably right in assuming that it is the egg ribbon of Hexabranchus, but that is not the same as actually witnessing it being deposited. For the Forum to be a source of reliable information for you - and all other readers - I need to feel confident that any statement about an animal's biology or anatomy on the Forum is supported by first-hand evidence. I am happy for 'probable sightings' to be included, as long as we all know that we are not absolutely sure.
June 7, 2005
From: Kamal El Tawil
Here are some pictures of Hexabranchus sanguineus (spanish dancer) I have recently taken in the Egyptian Red Sea. They were taken at night except for the egg ribbon.
Locality: Marsa Alam, Egypt, Red Sea. Depth: 7 meters. Length: 20-25 cms. 25 May 2005. Photographer: Kamal El Tawil
I hope the pictures are interesting enough for the Forum.
Ktawil@yahoo.comEl Tawil, K., 2005 (Jun 7) Hexabranchus sanguineus (Spanish dancer) from Egypt. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13977
Thanks for these photos. This uniformly red colour pattern is the one illustrated by Ruppell & Leuckart (1828) in their original description of this species from The Red Sea. Your photos also show one of the characteristic features of Hexabranchus which is that each of the gills is attached to the body wall by an independent stalk. The name suggests their should be 6 gills [Hexa = six; branchus = gills] but sometimes, as in your animal, one of the main stalks may branch so it appears there are 7 gills, or even 8.
Can you confirm the egg ribbon is that of Hexabranchus? It certainly looks like it, but it would be valuable to know why you think so.
January 15, 2004
From: Nils Anthes
Many thanks for the hint that the presumed Hypselodoris is in fact a Spanish Dancer. One thing, however, puzzles me: After collection we left the slug plus the substrate we collected it from for one night in a container. The next day we found an egg clutch, which is depicted in the accompanying picture. It looks pretty much like a Hypselodoris clutch, doesn't it? When I checked the slug under a stereo-microscope on the day of collection I didn't see any egg-clutch. But, of course, I might have missed it, although the clutch looks pretty fresh, as well. Next time I'll be more careful…
email@example.comAnthes, N., 2004 (Jan 15) Re: Hexabranchus juvenile from the GBR. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/11888
If it layed this egg ribbon then clearly its not a juvenile Hexabranchus. I am not sure if you are collecting as well as photographing. If you have the specimen then there are 2 things to look for in the specimen which would give you a good idea whether it is Hexabranchus or not. In Hexabranchus the gills insert into the skin separately while in most other dorids they join together at the base into a single 'trunk'. In juvenile preserved animals the separate gills are not easy to see if there is some shrinkage, but it's worth having a look. The second thing to look for is the shape of the oral tentacles on either side of the mouth. In adult Hexabranchus there is a unique hand-like flap on each side of the mouth with a series of finger-like papillae around the edge. Again in juveniles this is only partly developed and my not be visible in a preserved animal but again worth looking for. If it is not a Hexabranchus then there are a number of cheomodorids which it could be. Have a look at the Chromodoris decora colour-group Page for a list of possibilities
January 10, 2004
From: Nils Anthes
Have you got any idea about this Hypselodoris sp? We found it in 17m depths in an algal patch on sandy bottom at Lizard Island, Great Barrier Reef, QLD, Australia. The colouration doesn't resemble very much any other Hypselodoris depicted in the Forum.
firstname.lastname@example.orgAnthes, N., 2004 (Jan 10) Hexabranchus juvenile from the GBR. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/11841
I think this little animal was specially designed to fool nudibranch workers. Despite appearances it is a juvenile Hexabranchus. You can see how the edge of the mantle is already beginning to fold over.
December 16, 2003
From: Erwin Köhler
here are 2 shots from the Philippines, Malapascua Island, Logon, divesite "Gato Nudibranch City"
showing how Hexabranchus sanguineus unrolls its mantle when disturbed, not swimming ...
length approx. 8cm
date 14 Oct. 2003
Erwin@Philippine-Sea-Slugs.comKöhler, E., 2003 (Dec 16) Hexabranchus sanguineus unrolling the mantle. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/11688
December 11, 2003
From: Gary Cobb
I just discovered that the gills of Hexabranchus - the Spanish Dancer -retract into individual 'sockets', probably about 8 of them when alarmed. As you can see in the attached photo. I always thought the gills where one whole unit! Is H. sanguineus the only species that has this feature?
The photo attached shows an animal that has a lot of white dots ... more than I have seen before. You beauty!
Location: Old Woman Island, Mooloolaba, Queensland, Australia
Site: Northwest Reef
email@example.comCobb, G., 2003 (Dec 11) Gills on Hexabranchus sanguineus. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/11576
Congratulations on discovering its secret. The apparently separate gills is one of the main characters for this genus, and its name Hexabranchus means 'six gills' a reference to the separate gills, the number of which can vary a bit. Have a look at Robert Sozzani's message where I discuss the gills in a photo he has of a juvenile animal
May 19, 2003
From: Roberto Sozzani
Again a Nudibranch I can't identify, maybe a juvenile Chromodoris?
Location: Sangeang Is. - Indonesia
Date: Aug. 2001
Thanks for your help!
firstname.lastname@example.orgSozzani, R., 2003 (May 19) Juvenile Hexabranchus. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9954
This little animal often tricks even the experts into thinking its a chromodorid but it is a juvenile Hexabranchus sanguineus. If you look carefully at your photo you will see that each gill is separately attached to the body, rather than being joined basally. This is characteristic of Hexabranchus.
May 2, 2003
From: Mary Jane Adams
I photographed these two Hexabranchus sanguineus on the same dive at Three Islets, Mergui Archipelago, Andaman Sea, Myanmar [Burma] on Feb. 27, 2003. They were crawling around on the reef in the middle of the day.
The slug in the upper image was 7cm long and 17 meters deep. The one in the lower image was 22-25cm long and 10 meters deep.
This is about as big as they see them in this area. The anterior end of the mantle is damaged revealing some fringed structures underneath.
Are these oral tentacles?
email@example.comAdams, M.J., 2003 (May 2) Hexabranchus from Myanmar. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9646
Thanks Mary Jane,
Yes the oral tentacles in Hexabranchus have this hand-like appearance, similar to the way the oral veil in Bornella has divided into a pair of 'fingered' [digitate] lobes.
April 29, 2003
From: Molly Ogden
My name is Molly Ogden of Califorina, and I am doing a Research Paper on the Spanish Dancer for my Marine Biology class. I am in 10th grade at Yucaipa High School. I was wondering if you could tell me anything spacific about this nudibranch, things that aren't commonly known.
Thank you for your time.
firstname.lastname@example.orgOgden, M., 2003 (Apr 29) Spanish Dancer Research Paper. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9752
There is all the information you are likely to need on the Forum - and there are references to even more information which you probably won't need. But since it is your research paper I'll tell you where it is on the Forum so you can have the satisfaction of finding it yourself.
Firstly, have a look at the species Fact Sheet. Also look at the messages attached on the bottom of that page as there is a lot more information included there. Also have a look at Page 2 for more messages. Make sure to follow the underlined links to further information. Also look at the paragraph on Deimatic Display in the Nudibranch Colour Page.
Good Luck with your project,
March 4, 2003
From: Bill Rudman
Could the person who recently sent photos of the Spanish Dancer - Hexabranchus - mating, to my email address please send them again. Some glitch in my email system caused the message to disappear just as I was about to open it
January 23, 2003
From: W.B. Rudman
Location: South Reef.
Bill RudmanRudman, W.B., 2003 (Jan 23) Hexabranchus sanguineus from Lord Howe Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/8966
January 9, 2003
From: Danny Van Belle
This, again very small, nudi was also filmed at Tulamben, [Bali, Indonesia] in May 2002, depth around 3 meters. Length about 1 cm. I can't identify this chromodorid?
It's not always easy to send pictures out of video. On a TV screen they're huge even the small ones and details are easily seen this however is difficult on the still images.
It's body is pinkish red with purple-red spots. Rhinophores white and orange topped.
Any idea ?
Danny Van Belle
This animal is very easy to misidentify. It looks very like Chromodoris decora or one of the other very similarly coloured species. It is however a juvenile of Hexabranchus sanguineus. [See message 1, message 2 for more photos].
November 18, 2002
From: Shawn Elston
I purchased a Spanish Dancer from a local pet shop in Hawaii not knowing too much about it. I have had it for a few days it seem to be doing fine. It has laid eggs on one of the corals. I do not want to disturb the eggs although I do not want to have them die after hatching. All that I have read up to now mainly states that the Hexabranchus sanguineus ( Which I believe I have) eats only sponges which I due not have in the tank and have not found in any stores to buy although some do carry them but are out of stock. I am a novice aquariist and care very much for the fish I have. Please inform me of what I should do. The Spanish Dancer is a lite red color/pink with some white, about 4-6inches long has, 4-5 sets of gills that i have counted it swims in the wave like motion.
Thanks for any help you can give.
Sorry but I can't give you good news. The biggest problem is that aquarium/pet shops should NOT stock nudibranchs unless they know precisely what the species they have eats, and have a ready supply of the food available. Imagine the outcry if they could not provide the right food for all the fish they sell. By stocking nudibranchs and selling them to customers, they are essentially condemning them to starvation and death. They are also ripping off their customers as well by selling you animals they know will die.
Have a look at some of the earlier messages on Hexabranchus, which are attached below yours on the Hexabranchus page [see also Page 2]. You will see they do eat a variety of sponges, but even if you went out on a reef and collected some sponges yourself, there is no easy way for you to identify if any of the sponges you have found are ones that the nudibranch eats. There would also be the difficult job of getting the sponges back to your aquarium alive and healthy, and then the job of keeping them alive in your aquarium while they are being eaten. Concerning the egg mass. Laying eggs is not necessarily a sign of well-being, in fact often it seems to be a sign of stress. Will the eggs hatch? Sometimes, especially when stressed, the eggs are infertile. Even if fertile, Hexabranchus produces free-swimming planktonic veliger larvae, which need to swim for some time in the plankton, feeding on microscopic plants. Such veligers rarely survive in normal aquarum setups. And since the larvae settle on their food when they are ready to become slugs, we are back to the food problem.
Sorry I can't give you better news,
September 9, 2002
From: Constantine Mifsud
I believe the first time that I heard of the Spanish Dancer was in one of Cousteau's documentaries, back in the 60's.
email@example.comMifsud, C., 2002 (Sep 9) Re: Hexabranchus - its common name. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7920
September 7, 2002
From: Jason Lewis
I just have a question. Where and when did the name Spanish dancer originate?
firstname.lastname@example.orgLewis, J., 2002 (Sep 7) Hexabranchus - its common name. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7913
Yours is an interesting question. It is based on the similarity of the ruffled edge of the slug's mantle to the edge of the dress of a Spanish Flamenco Dancer. However I have no idea where the name was first used, or who made it up. It is one of the few common names which is in fact used commonly, and unambiguously refers to Hexabranchus. If anyone can find an early reference 1950s? 1960s? or before, please let us know.
June 22, 2002
From: Valeria Safonova
Lately I was given a few sea slugs as a birthday present. It's quite a new animal for me and now I try to understand what to do with them. Thanks for the information of their feeding that I found on your site and the List of Food Habits, this weekend we will try to “fish” the right food for them (we are living on Comoros Islands). Amid them there is a very beautiful red species, which we call Spanish dancer and which resembles Hexabranchus sanguineus. I've read that it can grow till 50 cm. The question is if it is always the case that the adult is so enormous or it depends on something? At the moment it is 6 cm and I do not think that it will be possible to keep it in the aquarium if it becomes so big.
Thank you in advance,
email@example.comSafonova, V., 2002 (Jun 22) Size of Hexabranchus. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7328
What a beautiful place to live. I guess it is also a good place to see if you can keep nudibranchs alive in your aquarium because you can always put them back in the sea if things don't work out. I am not sure how long it takes Hexabranchus to grow so big, but if you are fortunate to get the right sponge for your 6 cm animal I am sure it will live in your tank for some time before you have a space crisis.
If you have photos or observations on sea slugs from the Comoros they would be very welcome.
May 10, 2002
From: W.B. Rudman
PHOTO: AM C127465, 7 mm long alive. 11 February 1981, off boat ramp, 3m, under piece of broken coral, Christmas Is., Indian Ocean. Photo: John Hicks
I am not trying to start a competition with Mary Jane over who's found the smallest Hexabranchus, but this one is a few millimeters smaller than the one in Mary Jane's message.
May 9, 2002
From: Mary Jane Adams
This is my candidate for the smallest Hexabranchus sanguineus record. It is 12 mm long. I found it under a rock about 8 meters deep at Nudi Falls, Lembeh Strait, Sulawesi, Indonesia.
firstname.lastname@example.orgAdams, M J., 2002 (May 9) Juvenile Hexabranchus sanguineus. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6852
Thanks Mary Jane,
They certainly don't look much like a Hexabranchus at this size, do they? Best wishes,
April 17, 2002
From: Marina Poddubetskaia
Here is Hexabranchus sanguineus which I photographed at the end of March, 2002 in Egypt during a dive cruise at the North of Red Sea, between Hurghada and Sinai mountains.
Data: approx 30cm long, 21 March 2002, "Umm Ush" / North Red Sea, 12m depth, night dive
It is the biggest Spanish dancer that I've ever seen.
email@example.comPoddubetskaia, Marina. , 2002 (Apr 17) Hexabranchus sanguineus from the Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6724
The bright red colour of your animal certainly lives up to the species name -sanguineus - which is derived from the Latin word for blood.
March 22, 2002
I am doing a 6th grade science project on the Spanish Dancer and i need to know what eats them and what they eat. I am having a hard time finding info.
firstname.lastname@example.orgStudent, 2002 (Mar 22) A report on the Spanish Dancer. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6515
Hexabranchus seems to feed on a variety of sponges. The most extensive list of sponge species apparently eaten by it is in a study by Francis (1980).
• Francis, M.P. (1980) Habitat, food and reproductive activity of the nudibranch Hexabranchus sanguineus on Tongatapu Island. The Veliger, 22(3): 252-258. (Figs 1-4)
He reports that it eats Ancorina acervus (Bowerbank), Callyspongia sp., Cliona sp., Haliclona sp., or Adocia sp., Mycale sp. , or Zygomycale sp., Pachastrella sp., Paraesperella sp., Petrosia sp., Stelletta sp., and Xestospongia exigua (Kirkpatrick). Others have reported it eating species of Halichondria sp. and Leucetta solida.
As to what eats Hexabranchus, I have no idea. Fish probably try to eat it but if you look at the section on Deimatic Display in the Defensive Colouration Page you will see that we think that they may be able to frighten off curious fish by startling them with their bright colour pattern.
I hope this helps you with your project
March 21, 2002
From: Stuart Hutchison
Here's some varied closeups of Hexabranchus sanguineus from Bali, Indonesia. They're a truly beautiful species, found in reliable numbers on night dives in the area.
Depths from 3m in the coral gardens to 35m on wrecks. Lengths are typically 30cm in this area. I have several shots with imperial shrimps aboard as well.
Hutchison, S., 2002 (Mar 21) Hexabranchus sanguineus from Bali. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6288
March 21, 2002
From: Stuart Hutchison
Here are some more shots from Bali, to accompany my earlier message.
email@example.comHutchison, S., 2002 (Mar 21) Hexabranchus sanguineus - oral tentacles. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6289
I have kept these photos separate because they show the peculiar and unique, hand-like oral tentacles found in Hexabranchus. In the upper photo we can see how all the 'fingers' are touching the surface of the rock, presumably giving the slug sensory information as it crawls along.
January 27, 2002
I took this picture of 2 huge nudibranchs in December 2001 at Apo Island - Philippines. Are these Spanish Dancers?
The were each about 25 cm long. (the picure was taken with a 20 mm wide angle).
Thanks in advance
firstname.lastname@example.orgReine, 2002 (Jan 27) Are these Spanish Dancers?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6046
Yes these are Hexabranchus sanguineus. At present we consider that there is only one species in the Indo-West Pacific but if you look at the other photos on this page you will see that there are a number of distinctive colour forms which probably need to be looked at in more detail before we can be sure.
Your 25cm animals are quite large but Marli Wakeling in an earlier message reports some at about 60cm long.
December 17, 2001
From: Allan Connell
Do you know this species? I collected it at about 30m on reef off Park Rynie on the east coast of South Africa (KwaZulu-Natal). I will need to get back to you on the date. Note the branched gills. I thought it might be a species of Glossodoris.
With greetings and best wishes
email@example.comConnell, A, 2001 (Dec 17) Hexabranchus? from South Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5818
I am pretty sure this is strange colour form of Hexabranchus sanguinea or perhaps a distinct species? Have a look at the photo of a blue Hexabranchus from Bob Bolland in Okinawa. It is very similar. It seems in your photo that each gill has a separate insertion into the body wall, which is a characteristic of the Family Hexabranchidae. At present only one species of Hexabranchus is recognised, but this may change as more material become available for research.
December 14, 2001
From: Joyce Zwiener
My name is Joyce Zwiener and I am a salt water aquarium hobbyist. Recently I purchased a Spanish Dancer from my local pet store and was wondering if it would be harmful to keep such a creature with coral. According to your web page they eat sponges. I was wondering if they would eat other things such as algae, brine shrimp, etc. It is a rather large specimen so I would like to keep him happy and healthy. If you could help I would greatly appreciate it.
P.S. If I could ask one more question .... The other day I found a long red sponge-like ring that the Spanish dancer seemed to have sloughed off. This was found the morning after I had introduced him to the tank. After I read your web page on Spanish dancers I was wondering if this could be an egg sack?
firstname.lastname@example.orgZwiener, J., 2001 (Dec 14) Spanish Dancer?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5826
Hexabranchus is a sponge feeder, so it would be unusual for it to eat other things even in aquarium conditions. So the most likely thing is that it will slowly starve. Unfortunately there is no way it will remain happy and healthy if it can't find appropriate food. The red ring you mentioned is almost certainly an egg ribbon - unfortunately laying an egg ribbon like this is often another sign of stress.
Sorry I can't offer better advice
September 7, 2001
Dear Dr Rudman
Do you have any information on the nudibranch the Spanish Dancer? My daughter is doing a school project and any information you have would be greatly appreciated.
email@example.comBelinda, 2001 (Sep 7) Spanish Dancer. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5219
The scientific name of the Spanish Dancer is Hexabranchus sanguineus. If you click on that name you will be taken to the first of 2 pages with information and messages on the Spanish Dancer. For example if you scroll down the page beneath this message you will find earlier messages arranged in date order. If you look through all the messages you will find lots of information and beautiful photos of this fascinating nudibranch.
For more general informaton on nudibranchs click on the General Topics button at the top of the page (or in the yellow bar above) and you will get an index of more general topics. Hope this will help your daughter in her project,
August 28, 2001
From: Luigi Montevecchi
I observed this Hexabranchus sanguineus at Sernaka Island, Egypt, (Red Sea) during a night dive, August 12th, 2001.
The animal, about 20 cm. in length, was resting on a coral at about 7 meters (max depth: 10 meters, sand). The images belong to a digital video-tape that I recorded on a 3ccd Sony digital camera. After the first photograms I gently touched the dorsum of the nudibranch, and it started to dance in the water (see attached picture).
firstname.lastname@example.orgMontevecchi, L., 2001 (Aug 28) Swimming Hexabranchus from the Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5153
Thanks for these beautiful photos of Hexabranchus swimming. Your photos clearly show the complex nature of its swimming ('dancing') movement. It is a combination of a dorso-ventral flexing of the whole body and a muscular wave which runs along each side of the mantle, causing the wing-like flapping of the mantle edge. It is amazing how long they can continue to 'dance' before tiring. I have watched one swimming for over an hour. Has anyone else made any observations on how long they can swim?
August 28, 2001
From: Luigi Montevecchi
Following my photos of Hexabranchus sanguineus swimming, here is a photo of Hexabranchus and an egg mass. I took this at Abu Kifan reef, Egypt, (Red Sea) on August, 17th, 2001, at 11 meters.
email@example.comMontevecchi, L., 2001 (Aug 28) Eggs of Hexabranchus sanguineus. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5160
August 3, 2001
From: John Hoover
Concerning Scott's message. Another informal observation on Hexabranchus "aureomarginatus" from Hawaii. In my experience, Hexabranchus with white patches and a yellow margin are often seen in the open by day whereas the all-red ones seem to be active mainly at night. They also tend to be smaller. I've never seen a really big Hexabranchus with white patches.
firstname.lastname@example.orgHoover, J., 2001 (Aug 3) Re: Hexabranchus 'aureomarginatus' in Hawaii. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/4995
July 30, 2001
From: Scott Johnson
I'm sure you are correct in your id of Anuschka's dorid as a juvenile Hexabranchus. Attached are three shots of small individuals taken in Hawaii. The smallest (Lower Right Photo) is less than 20mm in length. The other two are both over 30mm. The yellow margin is present in all of them. Although I suspect these are indeed young Hexabranchus sanguineus, a yellow margin was one of the features Ostergaard used in his 1955 paper to distinguish his new species Hexabranchus aureomarginatus. While this species is generally considered yet another form of H. sanguineus, I have some doubts. But I'll put those in a separate message.
Johnson, S., 2001 (Jul 30) Juvenile Hexabranchus from Hawaii. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/4952
Thanks for this nice series of photos. They certainly show the progression to a more 'Spanish Dancer' looking animal.
July 30, 2001
From: Scott Johnson
As promised, here is some information on the 'species' or 'form' Ostergaard named Hexabranchus aureomarginatus. They are common in Hawaii, but less so than the larger Hexabranchus sanguineus. Those that fall into the aureomarginatus form always have several features in common that distinguish them from sanguineus. These are the yellow margin, opaque white frosty-like patches on the dorsum, and orange (rather than red) rhinophores. While I have not looked extensively, I have not noticed any consistent differences between the radulae of H. sanguineus and H. aureomarginatus, but one other interesting difference is in the egg masses. Typical H. sanguineus produce large, dark pink, ruffled egg masses similar to that pictured in David Harasti's message. The aureomarginatus form produces much smaller, much less ruffled, and light pink egg masses as shown in the attached photo. Adding more confusion to the issue is another Hawaiian Hexabranchus described by Ostergaard, H. pulchellus. More on that in another message.
Johnson, S., 2001 (Jul 30) Hexabranchus 'aureomarginatus' from Hawaii. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/4953
I wondered how long before the colour 'forms' of Hexabranchus became a talking point on the Forum. I'll keep them all under the 'umbrella' of Hexabranchus sanguineus, but as Bernard Picton would almost surely say, this is a question we might invite the molecular chemists to have a look at. I like the egg mass difference.
July 30, 2001
From: Scott Johnson
Along with H. aureomarginata, the other 'species' of Hexabranchus described by Ostergaard was supposed to be spotted ['H. puchellus']. We do see spotted Hexabranchus occasionally, but so far all those I have looked at have been juvenile. The Upper and Lower Right photos are of animals in the 20mm range. The other one (Lower Left) is about twice that size. Although similar in size to the juvenile H. sanguineus sent separately, they do have quite a different appearance.
Johnson, S., 2001 (Jul 30) Hexabranchus 'pulchellus' from Hawaii. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/4954
Thanks for these photos. The difference from 'typical' H. sanguineus is indeed quite marked.