Opisthobranch defence mechanisms
PHOTO
Defensive mantle gland secretions streaming from the chromodorid, Glossodoris cincta. Photo: Danny Van Belle.
With the loss of the shell, opisthobranchs have evolved a whole series of ways of protecting themselves from attack by predators. Here are some of the main strategies.
• Camouflage. One widespread method is to hide from predators by having a colour, shape and/or texture which matches their food or background environment.
• Warning colouration. Many species with bright colour patterns are full of distasteful chemicals. Others with stinging cells or toxic glands have brightly coloured tips.
• Chemical Defence The skin of many many opisthobranchs contains distasteful and sometimes toxic chemicals.
• Behavioural strategies. Many opisthobranchs are mainly active at night when predators are asleep or cannot see them. Others are able to swim for short periods when disturbed, and so escape predators.
Have a look below for some specific areas of interest:
Autotomy
Chemical Ecology
Camouflage
Mimicry
Defensive colouration
Defensive mucus and mantle glands
The aeolid cnidosac
The aeolid cerata
Swimming in opisthobranchs
Sea Hares - chemical defence
Sea Hares - attack & defence, ink glands
References to defensive chemicals in Phyllidiidae
References to Acid Glands & Acid secretions
Rudman, W.B., 2004 (July 27) Opisthobranch defence mechanisms. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/defgen
Related messages
Which slugs are toxic?
February 25, 2005
From: Mhairi Todd
Hi,
I'm writing an essay about sea-slugs for my university course. I was wondering if you knew of a list or a website where I could find out which sea-slugs are toxic?
Thanks
Mhairi
s0233676@sms.ed.ac.uk
Todd, M.A., 2005 (Feb 25) Which slugs are toxic?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13225Dear Mhairi,
The Sea Slug Forum is much more than message board. Out of interest I just used the Forum search engine and searched for 'toxic'. It gives you a list of messages, Fact Sheets, references and links which should give you more than enough information for your essay.
Best wishes,
Bill Rudman
What are their enemies?
November 13, 2002
From: Debbie Goodman
To whom it may concern,
My daughter is in Grade 6 and they are doing a report on "Gastropods". She has a lot of information on sea slugs, etc but she has had trouble finding out their enemies and why? If you could send me any info on their enemies I would appreciate it.
Thank you
Debbie Goodman
British Columbia, Canada
kdgoodman@shaw.ca
Dear Debbie,
A gastropods first line of defence is its shell. So youe would think that sea slugs, which have lost their shells, would be 'sitting ducks' for any hungry animal passing by. Sea Slugs, and nudibranchs in particular, have developed a fascinating variety of ways to defend themselves. If you have a look at the Defensive Strategies Page you will see a number of links to pages with more detailed information.
For animals with such complicated defence mechanisms, we know remarkably little about what actually eats them. I have started a Predation Records Page to accumulate this sort of information so have a look there to see how little we know. I hope this will give you and your daughter enough information for yur school project.
best wishes,
Bill Rudman
Sea slug research
October 17, 2000
From: Cathy Haynes
Hello my name is Cathy Haynes and I am in my final year reading zoology at Newcastle University, England. Right now I am looking into studying for a PhD.
One topic that fascinates me is defence and warning systems shown by seaslugs. I would love to learn more so if anyone could tell me where this kind of research is going on or where I could find out more, I would be very grateful
Thanks
Cathy Haynes
c.r.haynes@ncl.ac.uk
Haynes, C., 2000 (Oct 17) Sea slug research. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3177Dear Cathy,
I guess you have found the pages on the Forum concerning defence. If not go to the General Topics page where you will find an index. Apart from the obvious pages on "Defence" look at the Sea Hare pages as well as a couple are directly relevant. One recent review of Sea Hare defences is also worth looking at.
As far as work in progress and where research projects on the topic are being carried out at present, I'm afraid I don't knoe of any. If anyone does, and would like to send information to Cathy could I ask that you send the Forum a copy as well so I can share the information.
Best wishes,
Bill Rudman.
Information on defence in Sea Slugs
April 26, 2000
From: Aubrey Rogers
I'm doing a school project and I need to know how sea slugs protect themselves
Aubrey Rogers
rcrogers@netzero.com
Rogers, A., 2000 (Apr 26) Information on defence in Sea Slugs. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2310Dear Aubrey,
There is a lot of information on defence in the Forum. I have made an Index Page which lists the major pages which should be of use to you.
I am not sure whether you know much about web pages, but in case you don't, if you click on any coloured and underlined words you will be taken to the page you clicked on. Just click on the Back button to get back to the page you started on.
Good luck with your project.
Best wishes,
Bill Rudman.
Defence in Sea Slugs?
April 2, 1999
From: Saeteurn
What do sea slugs have that keep them from being eaten?
Saeteurn
rSaeteurn@yahoo.com
Dear Saeteurn,
I have put your message on the Opisthobranch Defence page. If you go to the top of this page you will find a list of other pages to look at. These will show some of the many different ways Sea Slugs protect themselves by using, colour, nasty chemicals, stolen stinging cells and various special behaviour patterns.
Each page has some pictures and an explanation at the top and below that are any messages that have been sent in and answered. Its worth have a look at the messages and answers because there is quite a lot more information there.
I hope this will help you. If you have any particular questions after having a look through the topics please let me know.
Best wishes,
Bill Rudman.
Defence in nudibranchs
October 15, 1998
From: Magdalena Caretti
Dear Bill Rudman:
I really appreciate your help.I have serious difficulties to find any review where your work is publicated, and so it happens with another authors because, at least at my university ,they don't buy any journal of molluscs .As far as i know in this country that kind of journals, so specific, only some scientists get them....And i don't know none of them.On the same way, since i have to do this special work(semminary) for November/ 3rd it make no sense to me start asking for post sending,that's why i'm trying to get as much information as i can by internet.
Well,i don't want to bother you .I just want to say i'm very gratefull with this kind of sites ,i never thought someone so far could be interested on answer me.Thanks a lot.
Magdalena Caretti.
Universidad de Buenos Aires.
Argentina.
fcaretti@tournet.com.ar
Caretti, M., 1998 (Oct 15) Defence in nudibranchs. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/264Dear Magdalena,
Glad to be of help. The advantage of websites such as the Slug Forum is that an answer to you is available to a much wider audience, so as far as I am concerned it is a very effective way to spread information.
Best wishes...Bill Rudman
Nudibranch Defence Mechanisms
October 14, 1998
From: Magdalena Caretti
26 September 1998
Hello!
I'm a student from Argentina who's interested in the different kinds of defenses that have these animals, specially in that wich includes the color as an important fact.May be these words will help you to understand in which i'm interested :
-Autotomy
-Criptic
-Mimic
-Aposematism
-Camouflage
I'll sincerely apreciate any information you could send me.
Thank you.
Magdalena Caretti.
Address: M.T de Alvear 2371. 2C
CP(1112). Buenos Aires.
Argentina
Telephone/fax:822-4335
fcaretti@tournet.com.ar
Caretti, M., 1998 (Oct 14) Nudibranch Defence Mechanisms. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/258Dear Magdalena,
Sorry for the delay in answering your question but I have used your question as an opportunity to post quite a bit of material on the subjects you are interested in on to the Slug Forum. If you check out the topics I have listed at the top of this page I hope you will find some answers.
Best wishes,
Bill Rudman.
