Need Help with Polyp Eating Nudibranch questions and ID

[Witch-King]

Hi Dr. Ron. I was referred to you by a friend who works at a local fish store. I have 2 questions one on an ID and another more serious about an Aeolid Nudibranch that I recently found in my tank. I’ve spotted this creature a few times after lights off, but have never been able to identify it. It is very thin and long total length probably 4 to 6 inches. It seems to have the ability to stretch even longer while moving thru the tank. It is smooth unlike a bristle worm and its color is white with a red line that travels from its head to the end of its body. Sometimes I spot it scrunched up on a rock kind of like a snake, but not as well coiled. I believe that it is nocturnal, because I have never spotted it in full daylight. I haven’t noticed it disturbing anything in the tank and for that reason I won’t remove it unless you suggest otherwise. The second question is more of a major concern of mine. I recently ordered some zoos/polyps over the internet. After losing some colonies that were in tank for some time I had a feeling that something strange was going on. It wasn’t until about 2 weeks after I placed the new zoos in my tank that I noticed a Nudibranch eating my favorite polyps. I removed the Nudibranch which you can view in my gallery. This was the only large one I found. I then started to notice babies on the other polyps in the tank as well as a some eggs on one colony of zoos. I fresh water dipped all colonies about 3 times since this dilemma occurred. I removed all eggs and added a sixline wrasse in hopes of ridding any leftover baby nudibranch that I may have missed. Its been over a week and I have not noticed anymore Nudibranchs on any zoos (The zoos at this time all look great). I was hoping you could give me some information on this type of Nudibranch and what steps I could take to make sure they do not return. For precautionary measures I recently purchased a small quarantine tank incase they do end up returning. If they return I will move all zoos to the quarantine tank while giving more fresh water dips. My attempt will be to starve out the main tank, but I just don’t have enough information on how long the colonies would need to be quarantined in order for this idea to work? Sorry for the long thread, but I’m really desperate to make sure that I don’t lose anymore zoos as I care for them greatly. Any information on these topics would be greatly appreciated.

Thank You

[rshimek]

Hi,

I am afraid that without an image I really can't help you with the ID question. If you can get an image and post it, I probably can identify it, at least to major group.

Other than a generalized aeolid, I am afraid I can't help you with the identification of the nudibranch. The image just doesn't show enough detail. You can check through the images of aeolids at sea slug forum (www.seaslugforum.net) and see if you can find a close match. As to the problem of their removal from your tank, I really can't suggest much more to do other than what you are already doing.

Once you remove the last of the eggs, it should be no more than a month before the last of the babies show up.

If you put the zoanthids in to a quarantine tank, the nudibranchs should starve within 2 or 3 weeks.

Good luck! :D

[Witch-King]

Thanks for the reply. Next time I see the worm I will photograph it. I did do allot of research at the sea slug forum, but it seems they are little hesitant on giving advice on how to rid any Nudibranch problems which is understandable. I feel very confident that I may have beat this problem, but I just wanted to be on the safe side of things. The information you gave me on how long it would take to starve out the main tank is priceless Thank You very much.