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Meisen
01/14/2004, 01:34 PM
Anthony,

I read with much interest your article on Berghia sea slugs. Your articles are always a good read as you have a great informal style in your writing. Anyway, your article got my mind forming images of the little critters in my head, strangely familar to me for some reason. Later that day, I pulled one of my zoanthid rocks out of my tank on a lark. The colony had shown some strange recession that I was wondering about. When I put the rock in a shallow water tray, several "partially open" zoanthids caught my eye. I poked them a little, expecting them to close up but they didnt. Well, when one dropped off the colony, I realized they were sea slugs. I pulled 15 or so of them from the rock and found maybe 10-12 more from other colonies in the tank. I am sure there are (and will be) many more as I go on a little hunt every eve when the lights go down....

They only seem to be on certain zoanthid colonies in the tank and not others. Weird.

No new things have gone into that tank for at least 3 months so I am guessing whatever they are have been reproducing. I also removed 20 or so egg rings from the zoanthids, further supporting that theory.

So my questions:

Are Berghia adaptable feeders? Meaning when they run out of Aiptasia, do/can they resort to feeding on Zoanthids? I have some Aiptasia here and there in the tank but it has always stayed under control....did I just answer my own question? I am fairly certain they are feeding on the zoas however: direct observation of a slug eating tissue from a polyp, excessive recession of the tissue and polyps and the fact that all of them and their eggs are on the zoas and not near the Aiptasia suggest it. There were never any Aiptasia in the zoanthids as far as I can tell and some of them are aquacultured (by me) colonies.

Is what I have something else, maybe in same genus, that is a zoanthid specialist? I am fairly certain that my animals match your pictures exactly. I will work on some pictures though I wont be able to get anything as close-up or detailed as what you had on your article.

Last question: does anybody want to buy some Berghia sea slugs? Just kidding, I dont want to do anything with them until I figure out what is going on and if they are a danger to zoas.

Sorry for being so long winded, any help is much appreciated....

Mark

Skipper
01/14/2004, 08:43 PM
Hey Mark. That's a different nudi that specifically feeds on zoanthids. I've heard of several folks that have them. To an avid SPS keeper who originally made the mistake of adding zoanthids to his/her tank.... they're a god send!!! I'm sure you'll find lots of folks waiting to take them off your hands. :D

Anthony Calfo
01/14/2004, 09:33 PM
Skipper has indeed said it all my friend... a different nudi.

And Berghia like many/ most nudibranchs are very specialized feeders (not readily adaptable at all).

Please do take some photos though and share them... I'd love to see them :) No worries either without fancy camera gear. Some compromises can be made - do make it easy on yourself and remove a specimen to a small solid colored cup or dish so that you can fill the frame as much as possible and push the limits of your camera's ability (too hard shooting through the tank and water at a distance without an off-camera flash and some sexy lenses).

with kind regards,

Anthony

Meisen
01/15/2004, 12:05 AM
Thanks guys, I really appreciate the help. I will work on some pics. I dont know if I can get anything detailed enough to differentiate them from Berghia but I will try.