Janolus sp. 1.
Order: NUDIBRANCHIA
Suborder: ARMININA
Family: Zephyrinidae
DISTRIBUTION
Tropical and subtropical eastern Australia.
PHOTO
Nelson's Bay, Port Stephens, New South Wales. March 1996. Lower photo showing raised caruncle between the rhinophores, a characteristic feature of the genus Janolus. PHOTOS: Peter Flockart. See message below.
Authorship detailsRudman, W.B., 1998 (March 3) Janolus sp. 1. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/janosp1
Related messages
Janolus sp.1 from sthn Queensland
July 12, 2007
From: Bruce Wilkie
Hi Bill,
I found these animals crawling around in the shell/sponge/soft coral rubble which had gathered in a depression. I counted nine of these animals in a area of about 2 square meters. I have identified then as Janolus sp.1. Could you please confirm?
Locality: Shag Rock, Point Lookout, North Stradbroke Island., 15 mts, Queensland Australia, Pacific ocean, 30 december 2006, rocky reef with sponges, hard & soft corals . Length: 30 mm. Photographer: Bruce Wilkie.
Many thanks,
Bruce Wilkie.
brucedwilkie@yahoo.com.au
Wilkie,B, 2007 (Jul 12) Janolus sp.1 from sthn Queensland. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19122
Dear Bruce,
Yes this is Janolus sp. 1. I can't make any suggestions on why they were congregated here. From the broken shell around it looks like a place where a lot of debris has been accumulating. All I can suggest is that it is a good place for their food bryozoan.
Best wishes,
Bill Rudman
Janolus sp. 1 from Port Stephens
July 3, 2007
From: Erik Schlögl
Dear Bill,
I think this is a specimen of Janolus sp. 1, as it is called on the Sea Slug Forum. It seems to have been caught in a scatological moment.
Locality: Fly Point, Port Stephens, 20 meters, New South Wales, Australia, Pacific Ocean, 3 October 2005. Length: 2 cm. Photographer: Erik Schlögl.
I also noticed that one of the messages refers to this species as Janolus "carinate." I don't know whether the author of that message ever got back to you about the source of that name - Helmut Debelius uses that name in his book, but considering the critical remarks on this book in the book review section of the Forum, I don't think that can be taken as authoritative.
Best regards,
Erik
Erik.Schlogl@uts.edu.au
Dear Erik,
Yes this is Janolus sp. 1.
Now and then I get messages from members of the public who can't see why intelligent people might spend their time discussing the wonders of sea slugs - the politer ones usually include phrases such as 'get a life! ' etc ... I shudder to think what they will think of your series of photos. Personally I find them a wonderful way to show just where the anal papilla is in the Zephyrinidae.
Best wishes,
Bill Rudman
Janolus from Tasmania, Australia
January 3, 2007
From: John Smith
Hi Bill,
I haven't been able to identify this nudibranch. It was initially on a kelp frond waving around in the swell and encouraged onto this weed for the photo.
Locality: Waubs Bay (off the Sea Wall), Bicheno, 6 metres, Tasmania, Australia, Tasman Sea, 18 November 2006, 20 metres offshore amongst kelp.. Length: 40 mm. Photographer: John Smith.
Can you help?
Regards,
John
jmsm37@bigpond.net.au
Smith, J.M., 2007 (Jan 3) Janolus from Tasmania, Australia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/18860
Dear John,
This is probably the species I am calling Janolus sp. 1 on the Forum
Best wishes,
Bill Rudman
Janolus from Port Stephens, eastern Australia
August 4, 2003
From: Janice Hempstead
Dear Bill,
Have been looking through some old slides among my unidentified species collection. Now, with your Forum, perhaps they can finally be identified. Help! please.
Photo taken was at Fly Point, Port Stephens [New South Wales, Australia] Oct 1991, in maybe 15m. 2/1 lens.
Janice
hempies@idl.net.au
Hempstead, J., 2003 (Aug 4) Janolus from Port Stephens, eastern Australia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/10343Dear Janice,
This is a species we are calling Janolus sp. 1 at present
Best wishes,
Bill Rudman
Janolus 'carinate' - Perhaps
January 7, 2001
From: Stuart Hutchison
Dear Bill,
I think this is Janolus carinate. They were about two inches long in 10m of water at Nelson Bay, NSW in Dec 1997. As usual, they soon found each other and mated.
Stuart
hutchco@tpg.com.au
Hutchison, S., 2001 (Jan 7) Janolus 'carinate' - Perhaps. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2989Dear Stuart,
Thanks for the photos. It is what I am calling Janolus sp. 1. I would be interested in where you got the name Janolus carinate?
Best wishes,
Bill Rudman
Janolus from Port Stephens, NSW
May 24, 2000
From: Peter Flockart
Dear Bill,
Here is a slide taken some years ago at Nelson's Bay, Port Stephens, New South Wales.
I have tried to identify it from the books I have but are no closer than deciding it is an aeolid. Also I have been unable to locate any information regarding aeolids that eject fluid when touched.
It was found at night on a frond of the brown alga Ecklonia in about 1 meter of water, about 10 meters off shore, March 1996. The shoreline here consists of a sandy beach that gives way to a kelp covered rock platform which falls away to ledges at 10 meters and a sandy bottom at 12 meters.
When touches the creature could move fairly quickly but if disturbed enough it would eject a stream of milky white fluid from the protrusion in the middle of the body.
Regards,
Peter Flockart
nelson01@bigpond.com
Flockart, P, 2000 (May 24) Janolus from Port Stephens, NSW. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2440Dear Peter,
This is an unnamed species of Janolus which is reasonably common in south eastern Australia.
Although they look somewhat like aeolids, they are more closely related to the arminids. If you go to the Species List and have a look at the animals in the SUBORDER ARMININA you will get an idea of its closest relatives.
Most nudibranchs, because they have lost their shells, have developed some means of protection from predation. Have a look at the mantle glands page for some information on those that have some sort of chemical secretions from their skin. Others are able to drop off parts of their body when attacked [see autotomy page]. Only the aeolids have stinging cells in their cerata.
Many species of Janolus drop of some of their cerata when they are attacked, and as you have seen, some can produce a milky secretion, no doubt as a deterrent.
The large warty lump between the rhinophores [arrow in lower photo] is called a caruncle or inter-rhinophoral protuberance by others. It is characteristic of the genus Janolus and as far as I know its function was unknown. Perhaps your observation of it secreting a milky substance suggests a defensive role.
Best wishes,
Bill Rudman.
Janolus from Port Stephens
March 3, 1998
From: Wayne Ellis
Hi Bill,
Any comments on this nudi found off Fisherman's Co op, Port Stephens, New South Wales, 9m Night dive. 8 December 1984
Regards
Wayne Ellis
glaskin@ozemail.com.au
Ellis, W., 1998 (Mar 3) Janolus from Port Stephens. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/75Wayne,
This is one of a number of unnamed species of Janolus which are known from Australia. Despite looking like aeolid, with cerata covering their backs, species of Janolus (and the related Madrella and Caldukia) are more closely related to the arminids. They feed on both branching and encrusting bryozoans (lace corals) and it is likely that different species have specific bryozoans they prefer as food. The species in your photograph is known from the Great Barrier Reef and as far south as central New South Wales. It is also reported from Lord Howe Island and New Caledonia.... Bill Rudman
