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FAQs about Nudibranch Compatibility, Control

Related Articles: Nudibranchs, Sea Slugs,

Related FAQs: Nudibranchs 1, Nudibranchs 2, Berghia Nudibranchs, Nudibranch Identification, Nudibranch Behavior, Nudibranch Selection, Nudibranch Systems, Nudibranch Feeding, Nudibranch Disease, Nudibranch Reproduction, Sea Slugs, Marine Snails 1, Marine Snails 2, Marine Snails 3,

Zoa Eating Nudis        6/21/19
<Hello Branko>
We are having an issue with Zoa Eating Nudis, we've used Aquaforest Dip after acclimation of corals on import. It does wonderful job and kills off adults, however after a while eggs hatch and they start re appearing. Then we redo dipping on all our corals... its very time consuming and Nudis eventually come back.
<Yep, they always return>
While looking for more permanent and easier to administer solution, I've come across posts suggesting use of Salifert Flatworms exit.
<Have worked for me>
Some swear by it, while others say multiple dosage is required, 4times recommended dose for flatworms. We tried that too, yet Im still seeing happy Nudis munching on my Zoas :( Is there any chemical way of killing them off while not harming corals, ideally putting solution into the frag tanks, or chemicals that we can dip in that will take care of the eggs too. If not what type of marine life would you suggest to use to fight this pest. I would prefer dealing with them with Chemicals / inverts rather than fish. I try to keep my frag tanks fishless, to ensure no type of protozoan parasite will be sold to customers along with the frags.
<Unfortunately, they are never completely eradicated by just adding chemicals or dipping, however, I suggest to dip/bath your Zoas for 5-10 minutes in a RO water/malachite green solution. Another “marine life” option could be the Yellow Coris Wrasse (Halichoeres chrysus), I know you don’t want to introduce fish to your frag tank but this one has proved effective.>
Thanks in advance, B.
<Please do keep us posted. Cheers. Wil.>

Reef critter ID, input re comp.       3/20/17
Hi i need help with an id on this creature. I believe it's some sort of Nudibranch just don't know the exact name and whether it is a reef safe or not. Thanks.
Kind regards,
<Is a Nudibranch... don't recognize the species right off; but would keep an eye on... IF it's eating something/s that aren't of interest to you; I'd keep. Bob Fenner>

Quick question about Aiptasia problem. Lions eating Berghia?    7/30/14
Hello, I've been in a huge search for days for the cure of my infestation of Aiptasia. I have had the tank for over 8 years, but these for about a year of that. Been keeping them under control, but would like a constant non chemical approach and I am starting to add corals to my tank so I want to get rid of them so they don't harm anything new. I read that the Berghia Nudibranch eats them, and I am very interested in getting them. Which stems my question. I have a dwarf lionfish. It is on frozen/ freeze dried foods, and I have snails and crabs in my tank that it doesn't bother at all. But I don't want to get these little guys to just have them be food.
<Doubtful... Nudibranchs, most sea slugs are unpalatable... one mechanism for avoiding predation is to taste bad>
The lionfish is the reason I haven't tried peppermint shrimp for the problem, even though I read those aren't a guaranteed solution. Would you happen to know the answer to this question? I appreciate any help :)
Jessie (Dayton Ohio)
<Bob Fenner, St. Thomas, USVI>
Re: Quick question about Aiptasia problem   7/31/14

thank you very much!
<Welcome. BobF>

Orange and Yellow Nudibranch... Iatrogenic troubles... incomp.       5/18/14
Hi, I have a question regarding a Nudibranch I purchased last month. I have included a picture of him. Beautiful specimen, very interesting to watch. I bought him from my LFS, which is normally pretty solid. The Nudi came in as an extra.
<A bane of the trade... go ahead>

I saw him and asked about him. I was told they were not given a name, and as such could not sell it to me because they were not sure what it ate.
<I do like their honesty here>

The next week I came in and was informed that they had indentified the Nudi. I was furnished with a picture in a book, which identified the Nudi and said it ate only live red sponge.
<Mmmm; doubtful>

The picture looked exactly like the Nudi, so I went and bought a red sponge
<... there are many different types of reddish Poriferans. Some are NO fun>

and then came and got the Nudi. I do not recall what the Nudi was called, but I can find out.
Well, the Nudi didn't ever touch the red sponge. Since I've never had a Nudi(other than lettuce)
<And these aren't Nudibranchs... see WWM re Elysia>

I assumed he was eating and I was just not catching him. I came home last night and the Nudi was not moving, just sitting in the corner...not usual for the specimen from what I've witnessed. I also noticed my livestock in the tank not acting normal, so I kept and eye on the tank. This morning I woke up and the Nudi had not moved, so I picked him up and smelled him.
Dead. So I flushed him and tested the water.
Parameters are as follows.
Mg-I don't have a test

I know my trates a high, but this is a biocube with many anemones

and some sun corals. Only 3 fish, a potters angel
<Misplaced here>
and a pair of gold striped maroon clowns.
<These two too>

I struggle to keep the trates around 40, so 80 is high even for what I'm used to seeing. All my anemones were sucked up and not behaving normally.
<Opisthobranchs can definitely be trouble when they die, dissolve in small volumes>

Fish did not seem to be affected. I also have a basket starfish in there, which fell from his favorite spot and died. So I immediately did a 75% water change. The livestock is starting to do better(6 hours since water
change). The only casualty seems to be the starfish :(.
Anyway, my question is....can you help me identify this Nudi and what he eats?
<Not one I've see, photographed... and too lazy to get out my references... see the works of David
Behrens, or spend a few hours on "SeaSlug Forum">
Is there anything else I can do to ease the stress on my tank from the dying Nudi?
<Read on WWM re... can you see, use the search tool, indices?  Nudibranch compatibility...>
Thanks for your help!
<Welcome. Bob Fenner>


Hermit Crab and Nudibranch: Clibanarius cruentatus and Aeolidiella alba, IDs, comp. – 11/13/12
> Hi,
> <Hello, Lynn here this morning.>
> I recently brought 2 'Mexican algae hermit crabs' that were supposed to be reef safe, one of them I cannot identify the species... Any idea?
> <Yep, it appears to be Clibanarius cruentatus, aka the “Spotted Black Hermit crab”, which is in the family Diogenidae (left-handed hermits). Whether this species is completely “reef-safe” depends on your definition of the term. Hermits are typically omnivorous but can have tendencies toward being either more herbivorous or carnivorous.  What's important is that if/when their preferred food dwindles, and they get hungry enough, they will likely “sample” whatever else is available. Bottom line: keep an eye on any and all hermits - even those labeled as reef-safe, algae-eaters, or herbivores.  That is, watch what they tend to eat, make sure they have enough, and monitor for any damage to livestock.  It’s a good idea to supplement their food with meaty bits of marine origin, sinking pellets, and/or bits of Nori (dried seaweed sheets).  Please see the following link for more information and photos regarding Clibanarius cruentatus: http://www.wildsingapore.com/wildfacts/crustacea/othercrust/anomura/hermit/spottedblack.htm 
> More information on hermits here: http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/hermitcrabs.htm?h=  >
> Also found a Nudibranch on my live rock which I cannot identify.  He doesn't seem to have touched my corals.
> <That’s good to “hear”/read but do keep an eye on them as sometimes the damage isn't immediately apparent. You have what appears to be a species known as Aeolidiella alba (family Aeolidiidae). If you can get a close look at the base of the rhinophores (the knobby-looking appendages just behind the head), you should see either a fine reddish line, ring, or splotch (see photos at links below for comparison). Also reported, is this species’ odd appearance during locomotion as it “waves” or “jerks” its cerata (appendages along the back) back and forth.  Unfortunately, I wasn’t able to locate any information regarding the animal’s diet, but rest assured, it’s a carnivorous predator. These Nudibranchs tend to hitchhike on or near their food source so if your individual arrived on a recent coral addition, I’d remove it asap, and keep an eye out for others.
> Please see the following links for photos and more information:  http://www.seaslugforum.net/showall/aeolalba
> http://seaslugsofhawaii.com/species/Aeolidiella-alba-a.html 
> More information on Aeolids here: http://www.wetwebmedia.com/MolluscPIX/Gastropods/Opistobranchs%20Sea%20Slugs/Nudibranchs/nudibran5.htm?h= 
> Take care,
> -Lynn Z>

Re: Hermit Crab and Nudibranch: Clibanarius cruentatus and Aeolidiella alba – 11/13/12
<You’re very welcome.>
..he came with my live rock which had 1 single Zoa and a single mushroom as hitchhikers. I let the rock cycle and he is still alive and the Zoa and mushroom are fine so I don't know what he could have been eating to live.
<Based on what seems to be the common theme within this family, I’d say a Cnidarian of some sort. Every Aeolidiella species that I was able to find diet-related information regarding, listed one/several varieties of anemone as being their prey of choice. Interestingly enough, other genera within the family (Aeolidiidae) listed hydroids and Palythoa in addition to anemones so that adds to the list of possibilities. Whatever the prey, it’s possible that there may still be some small/hidden individuals left that are sustaining your Nudi. On the flipside, if it has already gone through the food supply, you will likely see the animal roaming about the tank for a short while, then one day it’ll just disappear. Take care, Lynn Z>
Re: Ahh, excellent as always. B – 11/13/12

Thanks Bob, it was a pleasant surprise to see that query in the inbox this morning.  I check in every day, looking for ID's but must be missing them.  
At any rate, it's always a pleasure to see what neat little critters end up in people's systems!
Take care and thanks again,

Re: Need help with id 11/21/11
Sorry about that, I was doing a Google image search. Here is a picture of the Nudibranchs in question.
<Neat! Looks like a member of the Eubranchidae, genus Eubranchus... and a great mimic of the green algae Neomeris (annulata)!>
There are two references on the page, and the information contained isn't helping. The two are Nudibranch 8/16/07 Nudibranch, Sea Cucumber or Sea Slug? Aeolid Nudibranch 6/18/07
<Is this a close enough guess for you? Need to remove of course if it is doing too much (predatory) damage. Cheers, Bob Fenner>

Re: Need help with id 11/22/11
What do you mean by predatory damage?
<? What this species of naked gill slug eats, chews on>
What is it that they eat or do?
Is it reef safe?
<? Why are you writing instead of reading where you were referred to? B>
Re: Need help with id 11/22/11
Oops! Didn't paste a referral. See here:
and the linked files above. B

Re: More Re: Need help with id, Nudibranch 11/22/11
I am sorry, but after 7 hours of reading and trying to figure out what this is, I have no idea. I looked at the species you mentioned and there is nothing that looks like it. Can you just tell me if it is good or bad?
<... likely "bad" as in what is this animal eating here? I would remove it if it is obviously doing too much damage. B>

Nudibranch Hitchhiker ID 7/1/11
Dear WWM,
I have been an avid reader of your site for several years, but this is my first time writing. I am hoping you can help me with the identification of a hitchhiker. Please see the attached photos. I found it in the filter sock of the sump during my weekly water change. My best guess is that it is some kind of Nudibranch or sea slug.
<The former>
I searched the WWM Nudibranch identification pages, and my mystery creature seems similar to one labeled a Nudibranch in the suborder Dendronotina, family Tritoniidae. Do you think that is what this is?
<I do>
I have a 75 gallon reef tank. Current inhabitants are 2 Ocellaris clowns, a yellow tang, a scarlet shrimp, a toadstool leather,
<Likely the principal food item>
a hammer coral, a torch coral, hitchhiker mushrooms, and a xenia frag.
All inhabitants have been in the tank for 3-4 years, with the exception of the xenia and shrimp. They were added two months ago. Based on the tank inhabitants, do you think my hitchhiker is friend or foe?
<The latter. I would remove these via siphoning>
Thank you for your help and the wonderful website.
<Thank you for being part of it, sharing. Bob Fenner>

Nudibranch good or bad? 6/19/11
Good afternoon all and happy father's day to the dads,
I have piece of live rock in quarantine, and I have been taking a few minutes every day to check to see what has come out. I've already found a tiny pencil urchin, and today I found this Nudibranch-like creature. It is very small, no more than 7 mm, and maybe 1 mm wide. It has blue antennae, a squiggly white line down its back which is outlined in orange, and the main body is black.
<Sounds/reads more like a flatworm to me>
I've attached 3 pictures of it,
<Mmm, no; nada attached>
but I understand if it is hard to see because it is so dang small. Is this a harmful hitchhiker?
<Not very at this size>
How do I rid myself of it, if it is harmful?
<Siphon it out>
I don't want to introduce anything harmful to my display aquarium. Please and thank you,
<I'd leave all in at this point... Bob Fenner>
Re Nudibranch good or bad? 6/19/11
<Does appear to be a Nudibranch... I'd still leave it. BobF>

Treating the tank for Nudibranchs 4/28/10
Hi crew.
<Hi Chris>
I have read tons of stuff related to my problem. I have Zoanthid eating Nudis in my tank.
<Bad news>
My problem is that I can't remove all of them to dip without completely dismantling the tank knowing that the whole process will need to be repeated to eradicate the next generation of Nudis.
<Dipping usually does not work anyway>
I have removed a couple from dipping small rocks and frags and very rarely see them.
<They have to be removed manually. The life-cycle is typically two --three weeks, so daily removal over this period is required. An hours work or more a day typically until they disappear after three weeks. Frustrating. http://www.wetwebmedia.com/corldisart.html >
I was hoping that treating the entire tank with Flat Worm Exit
<A Planarian killer http://www.wetwebmedia.com/fltwmchemcont.htm Nudibranchs are not Planarians. This is a shotgun approach, a 'hopeful punt' that probably won't work>
followed by a healthy water change
<Requires at least two, 50% changes, the same day, the first an hour or so after treatment. This is NOT something I would do, it will kill life in your system>.
and carbon would be a viable solution.
If so, do you have any specific methodology including dosage amount to pass on to me?
<No chemicals that I know of. Quarantine of invertebrates & live rock before adding to the main system to prevent introduction of these in the first place. Hours of manual labour to remove once they are in>.
Thanks for you attention to my problem.
<No problem Chris>

Re: Hungry Shag Rug Nudibranch? What? 2/23/2010
I had to throw the rock out it was rotting the tank and made the tank smell rotten.
<What? No; should have been cured elsewhere. Read:
I'm still trying to get my nitrates down
<... see WWM re>
from it
<What is "it?">
looked like a flower with petals but after closer examination I saw antlers or whatever and when touched the "petals" fell off. what really sucked was the lfs said "too bad we cant catch every thing" and to toss it before it spread so I was just SOL Thanks for your response though.
<... Fish out of luck? Kris, please proof your writing before sending. I can't make out what you're trying to state here, nor what you're trying to get at with the too-large images you've attached. BobF>

Re: Hungry Shag Rug Nudibranch 2/24/10
Sorry about my writing I was never good in English.
<Please... take your time. Re-read over what you write... perhaps show it to someone else before sending>
Anyways the pics were to show the Xenia when I purchased the rock or colony within 2 weeks this creature had destroyed the whole thing and I had to throw the rock out.
It was the Xenia that smelled rotten not the rock. I'm just hoping the Nudibranch didn't lay eggs.
<I do too>
Thanks for your responses
<Thank you for this clarification. BobF>

Flatworm Identification: Actually, A Nudibranch: Dendrodoris nigra or fumata -- 2/17/10
<Hello Cassdy, Lynn here today.>
Any idea what this might be?
<Yep, it looks like either Dendrodoris nigra or Dendrodoris fumata. Both are very common Nudibranchs from the Indo-West Pacific region that share the same variations in color, prey on sponges, and are often mistaken for each other. Where they differ is the gills (the feathery structures you see arranged in a cluster towards the posterior end of the animal) and the mantle (the frilly area skirting the animal). Dendrodoris nigra has many small gills, arranged in a relatively tight circle, whereas Dendrodoris fumata has a few large gills that can extend the width of the animal. Unfortunately, I can't quite tell in the best photo whether the gills are fully extended, or partially, so we're out of luck there. As for the mantle, Dendrodoris fumata usually has some sort of papillae (warty growths/bumps) on it while D. nigra's should be fairly smooth. Complicating matters is the fact that the papillae can be very small or very prominent. Again, I'm sorry to say that I can't quite see enough detail in the photos to determine whether these are present.>
I found it in my reef tank.
<It happens. These are very common Nudibranchs.>
Have taken out since. Should he be removed to separate tank?
<Unfortunately, these Nudi's only eat sponges (probably a specific specie), so unless you have a continual supply, the poor thing is doomed. If it were me, I'd opt for humane euthanasia as opposed to letting it slowly starve to death. For more information on euthanasia, please see the following links:
http://www.wetwebmedia.com/euthanasiafaqs.htm >
Pics attached.
<Thanks, I was able to enlarge/lighten them enough to see more detail, but unfortunately it wasn't quite enough to confirm for you which Nudi you have. However, you might be able to accomplish this on your own with a magnifying glass and the information supplied within the following links:
Dendrodoris nigra: http://www.seaslugforum.net/showall/dendnigr
Dendrodoris fumata: http://www.seaslugforum.net/showall/dendfuma >
I think it's some kind of flatworm,
<It's actually a Nudibranch, but the two are commonly mistaken for each other!>
..when I found it was thin and circled under liverock.
<That's fairly typical. These animals are usually nocturnal so they hide out during the day under rocks or within crevices, etc..>
Body is pure jet black with tiny white tips on antenna/eyes.
<It's a beauty alright!>
Any help would be great.
<Hopefully the above information will do, but if not, or you need anything else, please don't hesitate to contact me/us.>
<Take care, LynnZ>

Re: Flatworm Identification: Actually, A Nudibranch: Dendrodoris nigra or fumata -- 2/17/10
<Hello again!>
I just wanted to follow up with this. I did some reading and the closest thing I could find was a Scutus sp.
<Neat animals, but what you have is definitely a Nudibranch.>
I checked pics and I'm almost certain this animal has no shell whatsoever.
<You're right!>
The antennae have tiny white tips which other Scutus did not.
<Right again!>
It also has a bushy like appendage on its back portion of its body.
<Yep, those are gills.>
Looks a lot like the nematocysts of Nudibranchs.
<Sometimes the gills can be mistaken for various shaped structures/'cerata', present on the dorsal surface of some Nudibranchs, particularly the Aeolids. The cerata can be used for digestion along with defense (nematocysts). For more information, please see the following link: http://www.seaslugforum.net/showall/ceras >
I'm wondering if this animal is actually harmful.
<Dendrodoris spp. do pose a viable threat to their prey: sponges. Also, Nudibranchs can release a toxin upon death which can harm livestock. Risk increases with large Nudi's in small systems (less water volume to dilute the toxin). In cases of toxin release, a large water change and running carbon is advised.>
It's very beautiful and I would love to put it back into my display tank.
<It's indeed very beautiful, but after reading ahead and seeing the size of this animal, I wouldn't advise it.>
But I do not want to risk being injury to myself or other animals in the tank. It's about 6 inches in length when crawling.
<Yowza, I didn't realize it was that big! That helps quite a bit with the ID. Dendrodoris nigra supposedly only reaches about 8cm (just under 3 1/4") in length, while Dendrodoris fumata can be 10cm/almost 4' or more. I've seen Nudi's stretch a surprising amount beyond their supposed length, but if your animal is that length (and not stretched for all its worth!), then it's more likely that it's Dendrodoris fumata.>
I have it isolated in a Rubbermaid container with some live rock. It won't really eat any types of fish food I have introduced.
<It's unfortunate, but you're right, it won't eat any of those foods.>
Let me know if you need any more info. Would love to ID this guy.
<I think that thanks to your latest information we're probably good to go. I'd still check those gills and mantle though, in order to confirm or refute. Take care, LynnZ>

Re: Re: Flatworm Identification: Actually, A Nudibranch: Dendrodoris nigra or fumata -- 2/17/10
It's been in my tank for a year or longer.
<Evidently, it's had enough sponges available to sustain it thus far. You'd be surprised though, how long it can take for some marine animals to starve to death. What concerns me is that unless you have a very large tank indeed with a lot of rock and available sponges in it, a large Nudi such as yours could finally exhaust the food supply and die. Six inches of any animal dying/decomposing in a tank is a problem. Personally, I wouldn't take the chance, but it's ultimately up to you. If you feel it's worth the risk, go for it. Just keep an eye out for trouble and be ready to act. In cases where there's less risk, I advise people to keep an eye on the critter, and remove if/when it seems to be in decline. The problem with this critter is that you may not see it again, even after it's dead.>
So the food supply is def good for it. I just want to now if it's harmful? To me if touched accidentally or to fish or corals...
<There shouldn't be a problem if you accidentally touch it, but I would avoid all contact. Although there are no cerata with cnidosacs/nematocysts to actually sting you, you may be sensitive/have a reaction to something else on the skin of the Nudibranch. Different people have different levels of sensitivity to things. As for the fish and other livestock, with the exception of the prey sponges, they should be fine.>
Don't care about sponges!
<Awww, poor little sponges! Take care, LynnZ>

Re: Re: Re: Flatworm Identification: Actually, A Nudibranch: Dendrodoris nigra or fumata -- 2/17/10
Thanks for all your help!
<You're very welcome!>
I have a 300G system
<Whew, I was afraid the Nudi might be in a small system!>
..and run carbon 24/7 so if it did die - I doubt it could be much of an issue.
<Yep, that definitely lessens the possibility of a system-wide nuke.>
I do 80G wc a week as well.

Hungry Shag Rug Nudibranch, Xeniid pred. 2/8/10
Hi Crew:
I hope you can help. Two weeks ago I purchased a Xenia rock with approximately ten or so stalks, the next day they started to die off. I went into the store and they told me that the Xenia is temperamental
<Can be; esp. when moved... to "differing circumstances">
and to try an Iodine cleanse which I did. I examined the rock and found what I thought was an Anemone but not sure what kind and it was eating the Xenia . Through internet research I found it to be a shag rug Nudibranch.
<Aeolidia papillosa? I doubt this is the species here... This is a cold-water animal. Could well be something very similar however that is tropical>
how can I destroy it I before it goes on to something else?
<Yes... I would siphon it/them out, or use a pair of long tongs to extract>
I do like the Xenia and it has destroyed about 90% of the rock.
Thank you for any help and answers you can give it is much appreciated
<Could you send along a few close-up pix Kris? Bob Fenner>

Berghia Nudibranch/Compatibility 1/8/10
<Hi Rick>
I am thinking about adding some Berghia Nudibranchs to eliminate my Aiptasia problem. Do you now if anything will eat the Berghia? I have a Yellow Coris Wrasse, Peppermint Shrimp, Six Line Wrasse, Bicolor Blenny, Mandarin, Flame Angel, Lamarck Angel and a few tangs in a 125. your input will be greatly appreciated.
<Natural predators of the Nudibranch are Butterflyfish of the Chaetodon genus, and wrasses of the genus Thalassoma and Coris. Two species of Butterflyfish fish in particular that have been noted as being efficient predators are: Chaetodon semilarvatus, the Red Sea Butterfly and Chaetodon auriga, the Thread Fin Butterfly. With that being said, there is a good possibility that your Coris Wrasse may go after it. Some predators may prefer a certain specie of Nudibranch so the possibility of it going unharmed exists.>
<You're welcome. James (Salty Dog)>

Stowaway Nudibranch, Xeniid pred. 04/20/09
Hi crew :D
I recently bought a lovely colony of red sea xenia which was home to a Phyllodesmium hyalinum - the little Nudibranch fell off the colony when it was knocked off the rock work. While this may sound a bit sad I know, the little guy is rather lovely and although I have no wish for it to snaffle my xenia I'd like to know if I can help it to survive, short of putting it back on the xenia colony...
<If it is indeed a Xenia eating Nudibranch, chances are that it needs to eat Xenia in order to survive. However, you might be able to feed it any kind of Xenia. Thus, you might be able to set up a little biotope for it and just feed it xenia frags (if you can find such for cheap). The other option, you could ask your fellow reef aquarists if they have excess Xenia (many reef keepers do-- some even consider the coral a pest at some point).>
after all, I did purchase the animal albeit accidentally!
<I do sympathize, appreciate your sentiment here. I recall a friend of mine who fell so much in love with two beautiful Nudibranchs that hitchhiked on his sun corals, that he forgot about the sun coral and did everything he could to keep the slugs alive by buying dying sun corals from LFSs, just to feed them. Of course, I don't recommend this per se, but I do sympathize with any such love for Nudibranchs. I've also had them as hitch-hikers and always wished I could keep them. However, do know that these animals don't usually live that long (even in the wild).>
Will the Nudibranch ultimately cause the death of the xenia, or will its feeding habits do little more than limit the size of the colony?
<Well, firstly, please do send in a pic so that we can confirm that this is a Xenia eating Nudibranch. Secondly, *one* Nudibranch on a large, fast-growing Xenia colony, might not destroy the colony, but as you say, just keep it "mowed" a bit. The trouble is that the Nudibranch could likely reproduce. Within a short time, you might not just be dealing with one Nudibranch, but many many Nudibranchs... who would likely destroy the colony eventually.>
Many thanks,
<De nada,
Sara M.>

Re: stowaway Nudibranch 04/21/09
Hi Sara,
Many thanks for the reply - have attached a picture of the little guy.
<Wow, great pic! May I ask, what camera did you use? The slug does look like a Phyllodesmium hyalinum. Please see here:
You might even want to write in to this site with your story/pics, since it is noted to be very difficult to find/see in the wild. Thus, maybe Bill Rudman would get a kick out of seeing yours (or at least confirm the ID).>
Sara M.>

Re: Finger Leather 04/11/09
Sara M.,
The finger leather mentioned below did continue to show signs of spreading.
We fragged off the bad parts. During the night hours, we discovered what was causing the damage. Attached is a picture.
<Uh oh, looks like trouble!>
Can you confirm that it is a Tritoniopsis?
<I'm no Nudibranch expert, but based on the look of the thing (and where you found it), I would certainly feel safe assuming that that's what this is. Especially after reading the info here:
We believe that the circle design in the first picture sent was possibly the eggs from this Nudibranch. There are similar pictures on the Sea Slug forum. Would you agree with our assumption?
<Yes... now the real question, how will you get rid of them? I would
suggest quarantining the coral for starters.>Thanks again.
<De nada,
Sara M.>

Nice pic! RMF
Finger Leather 04/11/09
Forgot to ask, should we worry about any of these other corals we have in our tank? We have read that it typically eats soft corals.
Sun Coral
Tridacna Crocea
Blue Spruce Caulastrea
<Most coral eating Nudibranchs are very picky eaters. Most will only eat a few species or genera of coral (some are even specific to just one species!). As far as I know the Tritoniopsis elegans Nudibranch only feeds on Lobophyton sp. So your other corals should be safe from them.>
<Thanks for sharing the pics.
Sara M.>

Berghia Nudibranch Question -- 10/08/08 Hello, <Hi Nick.> I have been searching the web for days trying to determine whether or not Berghia Nudibranch will be toxic to my tank if/ when they die off. I have some Aiptasia which came in on some live rock I recently purchased. I'd say there is less then 100 that I can see, although some are large. Some info on my tank to give you a better idea of what I am dealing with: My tank is 90 gallons with a 40 gallon sump. I am currently running Phosban in a Phosban reactor and COULD switch to carbon to help remove any toxins the Berghia would give off. I also have an Octopus recirculating skimmer. I only have 2 Chromis and a couple hermit crabs at the moment. The tank is a month and a half old. There are lot's of pods crawling around the rocks. I want to take care of the Aiptasia without killing any of the other life in the rocks (sponges, worms, pods). I am just concerned that when the Berghia die off they will potentially poison the tank. <Those Nudibranchs referred to in the hobby (and older scientific literature as well) as 'Berghia' (actually they are a different genus and species) are non-toxic to your tank, even if they die. They have a life expectancy of at least 6 months. Are you concerned that they might starve to death when all the Aiptasia are eliminated? That should not be a problem, when they are short of Aiptasia they become quite active at night and if you are a little bit nocturnal too you should be able to collect them and give them to other hobbyists. Remember to breed them in separate small canisters before adding them into the display tank. Skimmers, mechanical filters and filter feeders remove most of their planktonic larvae and make it hard for them to multiply in a standard marine tank. I'd buy 3 and breed at least 15 to solve your Aiptasia problem. Also see here http://www.wetwebmedia.com/ca/volume_1/cav1i3/aiptasia_impressions/aiptaisia_impressions.htm and http://www.wetwebmedia.com/aiptasiaantoine.htm .> Thanks for your help, Nick. <Welcome. Cheers, Marco.>

Hypselodoris bullocki- one inch 07/20/2008 Hi I just want to know if this little guy could kill my 3 rays if he dies I have a 150 gallon ray tank( a back up 300 gallon for when they get bigger). And like all the other LFS they said Hypselodoris bullocki eats algae, (my fault I should know better to buy and not research) so if for some reason he dies, will it kill the rays? I have the Fluval FX5 filter and a 36x12x18 wet/dry filter. Will I be ok if I get him out as soon as he dies? I really hope he won't because he is beautiful. But just in case? I would bring him back but the LFS but it is an hour away. Thank you Michelle <<Yes, these will release toxins into the tank upon death, how much damage? Well, that all depends on how bug the Nudi is when / if it dies and how big / healthy the rays are. Personally, I would remove it. Thanks. A Nixon>>

Help! Zoa eating Nudis -03/16/08 Hi, I hope you can answer an urgent question- I recently noticed Zoanthids disappearing. Today lost several bam bams. I spotted 2- 1/4 inch long green Nudis. Googled them and identified them as Zoanthid predators. It said to use flatworm exit. I have some used it before and a different tank. I need to know if this will hurt my RBTA. <The problem with these types of broad scale "medications" is that you never really know what they're going to affect in a reef tank. It might hurt other animals in your tank indirectly. It will kill any flatworms you have (benign or otherwise) and this could also hurt other animals in your tank (some flatworms are toxic upon death).> The package material says it is safe for reef inverts but I would feel better if I got an expert opinion first. <Expert opinion? Hehe... will you settle for mine?> Need answer quick, those buggers are munching away at my Zoas as I type. <My advice would be to remove the Zoanthids to a quarantine tank, and try your best to remove all the Nudibranchs by hand (with teasers under a magnifying glass) and also find and scrape off all the eggs (cheap dental tools you can get at a pharmacy work well). The problem with using flatworm exit for Nudibranchs is that you usually have to use a dose on the order of 5 to even 10x the recommended dose. And who knows how safe or not safe such a treatment is for a whole tank? I wouldn't risk it. If meticulous removal of the pest doesn't work, I would try the flatworm exit, but only in isolation (if possible).> Thank you so much in advance Linda Mecher : ( <Good luck! Sara M.> <<RMF would try the "usual assortment" of probable small predatory wrasses here as well.>>

Re: (Follow up: to Eric Russell) New solution against Monti eating Nudis... New Weapon In The Fight Against Montipora-Eating Nudibranchs -- 03/10/08 Hi Eric! <<Hiya Dominique!>> I just made this discovery. Using camel shrimps (Rhynchocinetes durbanensis) to fight Montipora eating Aeolid Nudibranchs. <<Really?>> Never heard of that trick before. <<Me neither'¦though I must mention, I don't consider these shrimp 'reef-safe' at all>> Very interesting, have a look: http://www.korallen-zucht.de/index.php?article_id=52&clang=1 <<Ahh! A shrimp stocked 'cleansing tank' separate from the main display'¦and utilized like a hospital/treatment tank'¦though for a much shorter time period. Keeping a small tank with a few of these shrimp in it should be a simple thing; and an interesting display on its own to boot!'¦ Very cool!>> Ciao! Dominique <<Thanks so much for the input, my friend. Prendere cura! EricR>> Berghia Nudibranchs? 3/2/08 Hi Folks, <Hi Tyson!> I hope all is well with you. <It's going very well, thank you!> My question is in regards to some Berghia Nudibranch that I have recently found wandering my tank. <Okay> I have encountered several red and olive green colored Berghia, not your typical cream colored variety. The body shape and characteristics are identical to the specimens typically sold for Aiptasia control. <Could easily be something else within the same family (Aeolidiidae) or suborder (Aeolidacea). If you have the time, please look through the species listed under those names at this link for comparison: http://www.seaslugforum.net/specieslist.cfm .> I have one Aiptasia near the top of my tank that they seem to have no interest in. Instead I find them wandering my Zoanthid colonies. <Uh-oh. That concerns me, as Aeolids prey on cnidarians (corals, anemones, etc.). Please see the information/photos at the following link, as well as those within the links listed at the bottom for comparison: http://www.seaslugforum.net/display.cfm?id=18140> It's hard to tell if they are causing any damage because I have only seen four or five of them in the last few weeks. Do you think that these Berghia pose a threat to my zoo colonies or perhaps any other coral? <It's entirely possible. I'd keep a sharp eye on things and be prepared to act quickly. These Nudibranchs tend to be fairly specific about what they eat. If you haven't seen any damage to your Zoanthids, they may have a taste for something else.> If they are not eating Aiptasia, what are they eating? <Likely some other Cnidarian (if present) in your tank. It's also possible that their preferred food isn't available and that they're not going to be around too much longer. In the meantime, I'd keep a very sharp eye out for damage/loss. Please see this link for more information regarding Aeolid Nudibranchs: http://www.wetwebmedia.com/nudispt3.htm (also see related links within) http://www.seaslugforum.net/display.cfm?id=18140> Thanks! Tyson <You're welcome and good luck! Take care, -Lynn>

Stocking question, FOWLR, and Nudi comp. 2/29/08 Hi, <Chris> I'm planning my wish list for a 125g FOWLR tank that's been cycling with 90-100 lbs. live rock for about a month now, and I think I've narrowed it down to these 7: 1. Foxface 2. either a Tomato or Cinnamon clown 3. Arabian (aldabraensis) Pseudochromis 4. Flame angel 5. either a Desjardini or purple tang 6. Bluechin trigger 7. Lunare wrasse My questions would be: (a) Presuming I add one fish a month (more or less), and sufficient nooks/caves/bridges for the more passive fish to shelter, would all 7 ultimately be too much for a 125g? <Mmm, not too much, behaviorally or physiologically> If so, which would be best to omit? (b) Do you see any compatibility problems with this list? <Triggers are always a wild card, and the Thalassoma wrasse could "turn" mean... but likely no problems here> (c) In what order should they go for the best likelihood of success/no fighting? <The Dottyback and Siganid first, the Clown and trigger last> Everything I've read says the more peaceful ones first, which leads me to think Foxface/Desjardini, but I've also read that those 2 are better to put into a tank with established amount of algae. Right now there's coralline, macroalgae and sponges encrusting the rock, but not the filamentous stuff they'd probably graze on. If the choice was between the Desjardini or the Purple tang, which would be a better tankmate for the others on this list? <The Purple... the other gets too large...> .I read the purple tang is rougher, so maybe he'd hold his own better? <Should> On an unrelated question, a couple of Nudibranchs hitched on the live rock and one is laying eggs (a gelatinous looking trail with hundreds of little visible specks) on the top of the tank front glass, where the water flow is strong). I read that these guys are short lived in an aquarium, and when they die, they could poison the whole system, killing the other occupants. <Mmm, not so much here... this volume will dilute> Its such an amazing looking creature, but should I take it out before he runs out of food? <I wouldn't> It seems to be eating one particular sponge. What if these eggs all hatch and a bunch of them go down the overflow? <So be it> Ultimately, I'm concerned about the fish that I plan on putting in the tank. The articles I've read say that Nudis taste bad and fish don't eat them. <Usually so> I'm a little suspicious of the opinions I get at the LFS, so your help is greatly appreciated. Thank you in advance, Chris S. <I would enjoy them. Bob Fenner>

Nudibranchs, as pred.s on Acroporas -02/20/08 Hello crew, <Howdy> I very quick question for you. I have gotten some information from my supplier and would like some help. I have purchased a lot of various Acroporas in the past, (cultured only). My recent purchases have somewhat intrigued me. All the Acroporas, are dipped and placed in quarantine for 6 weeks. No matter what. However these corals are dying from the bottom up, and from the tips inward. After contacting my supplier he claims there is a huge problem with parasitic Nudibranchs industry wide and manufactures are scrambling to find a solution that will kill the Nudibranchs and their eggs. How you any information on this. I have sent some die off pieces to a lab friend, so I do not have any pictures yet. Thanks, I appreciate any help. <Hmm... AEF usually eat/kill from the base up and out. If your corals are dying from the tips in, that sounds more like a different problem. In any case, this is my favorite page/site on AEF: http://www.melevsreef.com/aefw.html You can see from the pictures what an infected coral looks like and how the infestation progresses. Another good article... http://reefkeeping.com/issues/2007-09/mc/index.php> Ann Marie Sara M.>

Best Predator For Montipora Eating Nudibranch? -- 12/12/07 Hi! <<Hello Dominique>> What would be the best predator against Montipora eating Nudibranchs (Aeolids)? <<This 'ideal predator' is likely another larger/different species of Nudibranch...and probably not readily available to the hobby>> Is it very likely to help? Very importantly, is it safe around small shrimps such as sexy shrimps? <<I've found little, in my experience, that will help with battling these pests. Even prophylactic dips seemed more harmful to the already stressed corals than the Nudibranchs...and although freshwater dips did kill the Nudis, they also killed the corals>> Would the six line wrasse (Pseudocheilinus hexataenia) be a good choice? <<Not in my experience. This and a couple other wrasse genera I've tried (Halichoeres, Cirrhilabrus) did not seem interested at all in these small pest Nudibranchs>> Any risk that this wrasse eats sexy shrimps...? <<Is a possibility>> One last thing, is it going to doom my mandarin (food competition)? <<The Pseudocheilinus will out-compete the mandarin, and unless the system is large (more than 100g), will also likely deplete the available food supply>> Many thanks! Dominique <<I'm afraid I don't have a simple answer for your problem. You can try manual extraction with tweezers (very tedious...and they multiply very quickly) and blowing/clearing the Nudibranchs from the affected corals with a turkey baster. Both of these tactics will work best if the corals can be removed to a bare-bottom quarantine tank to facilitate siphon removal of stray/blown-off animals/egg strands. I have seen these Nudibranchs 'cycle-out' on their own after a while, and without eating/killing 'all' their prey food items...though most all small colonies were lost. Do also check the reef forums (Reef Central, reefs.org) and see if someone there has had any success eradicating these pests. Regards, EricR>>

Re: Best Predator For Montipora Eating Nudibranch? -- 12/12/07 Thanks for the reply. <<Sorry it wasn't better news>> It's a depressing situation. <<Agreed 'though I must mention, it may have been avoided with quarantine>> I just read some people saying the six line wrasse helped them. <<Is possible>> I am skeptical about that given what you already told me. <<I can only relate my experience and the experience of others I have known>> So far it seems to eat a single species. <<The Nudibranch? Yes, it is quite common for these creatures to feed very selectively 'sometimes even only on a single prey species>> Even moved to the other end of the tank to eat some more of it while there was another Monti species in the vicinity. <<My experience with these Nudibranchs was that they fed only on the plating and encrusting species of Montipora'¦and completely ignored M. digitata>> But I don't know what they'll do when there is nothing left of that species they like. <<Hopefully they will just 'fade away'>> I also just read that they should eat all Montipora species. <<I disagree'¦ Some seem quite specific in their diet. Hopefully you will be lucky in this regard>> My tank is Montipora dominated. If they wipe out my colonies of digitata I think I may go out of the hobby. :( We shall see... Thanks again! Dominique <<My fingers are crossed'¦ Am hoping, betting you will be around for a while [grin]. Good luck my friend. Eric Russell>>

R2: Best Predator For Montipora Eating Nudibranch? -- 12/13/07 Am more relaxed about it today after a night's sleep, but was a bit freaking out yesterday. :) <<No worries re the 'freaking''¦ And I'm glad you feel better>> For sure you are right about quarantine, but there is one thing: the Nudis *appeared* just two months (exactly 57 days) after introduction of the new/latest coral in my tank. Is that not amazing!? <<Hmm, interesting'¦ Perhaps there was an incidental introduction/hitchhiker (Nudibranch or eggs) on an added piece of rock, macroalgae, even a fish'¦>> So to be bullet proof (at least with Montipora eating Aeolid Nudibranchs) I guess one has to do a three month quarantine. <<Mmm, well'¦not really practical, eh?>> Ok, will report to you on the final outcome in a few months... <<Please do!>> Thanks for your support Eric! Dominique <<Is my pleasure to assist. Eric Russell>>

R3: Best Predator For Montipora Eating Nudibranch? (Update) -- 02/20/08 Hi Eric, <<Hiya Dominique!>> Just to let you know about the final outcome of the Montipora eating Nudibranch invasion. <<Ah, okay!>> You were right about how specific they are in their diet. <<Indeed>> They do seem to be impossible to remove from a tank until there is no more food for them. <<Yep>> They also can move to the sump easily to follow their prey if one naively tries to hide a piece down there... <<Ha! Sorry, I know it's not funny, but'¦>> But they only eat capricornis, <<At least this particular species>> not even other plating Montipora. <<Mmm'¦'quite specific' indeed>> In fact there is a nice piece in my tank I assumed to be a capricornis as it looks very similar and was sold to me as such, but the Nudis make the difference. <<I see>> I made a little research since then and ID it as M. undata. <<Oh? Neat'¦>> So only two small/medium sized (capricornis) corals were affected in the end: nothing happened to the many digitata, danae, undata and nodosa. << Yay!>> So I won't be selling my tank after all... ;) Dominique << I'm pleased you've decided to stay in the hobby 'and I thank you much for the update. Cheers, Eric Russell>>

Zoanthid eating Nudibranchs 11/30/07 I recently found quite a few Zoanthid eating Nudibranchs in one of my tanks, we have a few that are plumbed together. We have pulled off as many as we can find, dipped them in an iodine solution and pulled off all the egg spirals we can find. <Good> The colonies that are infested are in QT now. My question is this: when the eggs that we haven't found hatch do they have a free swimming larval stage, and if so would a UV sterilizer prevent them from making their way into my other tanks. <No> Is there anything I can do other than quarantining them and pulling the Nudibranchs off with tweezers? Do you know of any fish that would eat them that I could add to my tanks? Thanks for all your help. Amanda <"Eggs develop and hatch as free-swimming veliger larvae with a rudimentary coiled shell. The shell is lost with the larvae metamorphosing into a miniature adult settling on the bottom." (WWM) More rapid, complete physical filtration might sieve them out. Bob Fenner>

Re: Hey Bob, its Niki. Got an anemone question here. Actually, now a predaceous Nudi. on Sarcophyton (elegans?) 11/21/07 You are the best! That site rocks. Thanks, Bob. One more question...have you ever seen/heard of a 'Yellow Fiji Umbrella' specific Nudibranch? <Mmm, have been to Fiji a few times, diving... seen yellow Nudibranchs there... Do you have a pic?> I found a few Nudis the same exact color of the coral latched onto some very unhappy Sarcos. <Bad... should be physically removed, search the soft corals for egg packets, those removed as well> They reminded me very much of smaller versions of the larger white Nudibranchs that we find on the Sinularia and such. The difference is that they mimic the yellow color of the umbrellas, much like the Nudibranchs found on P. cylindrica. I do have pics if you need to see them. Thanks, Niki <Please do send these along... have collected, and discourage the collection of the "Yellow Sarcos" from here, and Tonga... as for whatever reasons (I know naught) they don't often live for long... but have been so inobservant as to not notice these apparent predators. Be chatting, BobF>

Re: Niki here, w/ pic of our little yellow friend. Nudi feeding on Sarcos... 11/22/07 So here's the culprit. <Ah, yes. Nice pix> I found about 10 or so embedded very deep in the tissue, all hidden very cleverly within the ruffles of the Fiji Yellows. The only reason they came to my attention was the fact that I was treating all of my Alcyonaceans with Levamisole Hydrochloride due to a rampant infestation of the run-of-the-mill white Nudibranchs, mostly on my Sinularia. The little yellow guys started bailing off. I have included a pic next to the other Nudibranch so you can get a feel for the size. <Yes... reports up to 1"> The white Nudi is almost an inch long. All of the yellow ones were about the same size. Let me know what you think, thanks again, Niki <Mmm, I do think you are wise to be using a dewormer. Look for the spiral egg masses... and remove them as well. Cheers, Bob Fenner>

Nudibranch? Good or Bad? Hard to tell from the photo. -- 06/26/07 Hi Bob: <Hi Chris, You have Mich as your crewmember tonight.> It's been a few years, but any clue to what this is (see attached) and if it's going to cause some issues in my Reef? <Appears to be a Nudibranch, but I can't tell much beyond that from the photo. It is more helpful to have a view of the dorsal side than the ventral side when looking at sea slugs. Looks a little like an Arminid sea slug, but I wouldn't put too much stock in this. You may want to check the sea slug forum at http://www.seaslugforum.net/ > Some on ReefCentral seem to think it is a soft coral eater and I should remove it (them). <Is possible that this could be predacious on soft corals or other creatures in your tank. Nudibranchs generally don't have terribly long life spans.> Do these reproduce rapidly? <They are generally hermaphroditic, and self-fertilization is rare. So unless you have two or more in your tank reproduction is not likely. If there are two or more about, there is more of a chance of reproduction but captive rearing is generally quite difficult as there are specific dietary requirements. I don't think you need to worry about plague populations if this is your concern> Thanks!
<Welcome! Mich>
Chris Goldenstein

Nudibranch/Anemone Slime Upsetting Fish? Yep! 6/6/07 Hello, <Greetings, Mich with you today.> I had a quick question about the effects of Nudibranch or anemone slime on fish. I added a rock flower anemone, a couple Cerith snails, and a lettuce Nudibranch (I got a bit of hair algae for him to get rid of) into my tank today and while acclimating them and adding them into the tank a great deal of the slime they had produced while in their bags went into the water. <Yikes!> I tried to remove some of it but couldn't get it all. Anyway, about 2 hours after adding in these items my four fish (2 true Percs, a bicolor blenny, and a purple Pseudochromis) began to scratch their faces/ gills on rocks. They then stopped for a while but began to scratch again a few hours later. <Likely a reaction to the toxins introduced into the system.> I have had a problem in the past with ich but I made sure to quarantine all the fish for 6 weeks using hypo salinity and left the main tank free of fish as well. The hypo salinity seemed to work as all the fish returned to a relaxed state and their symptoms of ich went away so after their long quarantine period they were reintroduced into the main tank. It has been 2-3 months since this outbreak and they have shown no signs of ich since. I have also added no new fish into the tank since then. <Ok.> Basically, my question is whether or not their sudden scratching could be from the introduction of these new inverts and the slime they produced during their long journey from the fish store or if the fish have ich or some other parasite infestation again and just be chance they didn't begin to feel it until 2 hours after I introduced the new items? <Probably a result of the chemical hazards added to your tank.> After testing my water my results were normal. <Ok.> In your opinion, should I prepare for a possible parasite infestation or wait and observe the fish before acting? <I would wait and observe, though this stress response can weaken the immune system allowing parasitic organisms a more favorable foothold.> Also, do fish ever scratch on rocks to mark territory? <Mmm, not that I'm aware of.> I am guessing the answer is no but it was worth asking because my fish seemed to all scratch on the rocks around the same time and then suddenly stop almost in unison. <Again, no doubt a response to environmental stress. You should add an extra bag of carbon ASAP and consider a larger water change.> Thanks for any advice you can give me and sorry if this has been answered before. <Hope this helps. Mich>

Zoanthid Eating Nudibranch...Not Hydroids After all! - 01/25/07 Dear Crew, <<Hello Russell>> A couple of weeks ago I wrote to you that my four small Zoanthid rocks in my 11 month old tank were infested with hydroids. You offered good advice. Upon further observation, and research, these are actually small Nudibranchs. <<Uh-oh...not the "better" option>> They are about 2-6 mm in size, light brown, and very, very annoying. <<Indeed>> I dipped the four colonies in fairly concentrated Lugol's with a SG of 1.014. Then I did a flash FW dip. I don't have a pH meter, so I just added a small amount of tank water to the FW; hoping to buffer as well as I could. <<Not likely much of a factor here>> It seemed to work. All zoo colonies opened up and did well. <<Hardy little buggers those zoanthids>> But now- really, based on my research, not much of a surprise- two have the little creeper's back on them. <<Yep, a few adults/egg strings were probably still in the display while you were nuking the rocks>> My next step is to remove all four rocks and place in my QT, with periodic dips. <<A good move, though I would only perform the dips if/when the Nudibranchs are sighted>> The Nudis only seem to be going after my zoo's, and not my softies or LPS. <<They are likely "obligate" feeders on the Zoanthids>> No SPS in my tank yet... and certainly not until I take care of these Nudi's. I have heard Nudi eggs are hard to kill (I am a family physician and have the same problem getting lice eggs out of my patients' hair)? <<Usually more "resistant" to attempts to eradicate, yes...but I think your plan to remove the Zoanthids from the display will allow any remaining eggs to hatch and die out...not unlike leaving a tank fallow when treating an ich infestation>> Besides Lugol's (which, I swear, has to be the same Iodine I use to clean wounds in my office), <<Ahh, but it is mate! Lugol's Solution (named after the French physician J.G.A. Lugol...and also called IKI (Iodine Potassium-Iodide); Iodine, Strong solution (Systemic); and Aqueous Iodine Solution BP) is a mixture of 5% iodine (I2) and 10% potassium iodide (KI) in distilled water with a total iodine content of 130 mg/ml>> any medicated dips you can suggest? <<I think the Lugol's is fine>> I suspect the only thing I can do is QT, do freq dips and, essentially, use tweezers to pick them off for the next, say, three to five years... <<Ha! At least you have a plan [grin]>> It's ironic that hobbyists have the hardest time keeping the large, pretty Nudibranchs alive and, at the same time, can't seem kill off these prolific little buggers.... the Aiptasia of slugs. <<All comes down to providing an adequate supply of the appropriate foodstuffs my friend>> Thanks, Russell in KY <<Always a pleasure to assist. EricR in South Carolina>>

Montipora Eating Nudibranch Predator? - 05/26/06 Hello WWM staff, <<Hello Stephen> I recently noticed a small number (at least what I could see) of Nudibranchs consuming various species of my Montipora. <<Mmm, very bad...and their numbers are higher than you realize>> This was very disappointing as I have gone through a QT for everything, but obviously something slipped by my inspection. <<Indeed>> Over the past 3 weeks I have moved most of my Montipora to a frag tank where I inspect and manually remove the adults and eggs at least every other day. <<Prolific breeders, I would do this daily...if you're serious about eradicating the Nudibranchs>> Finding very few now and found none yesterday! <<Keep checking...a few weeks quarantine in order here>> I do however have 2 large colonies of M. digitata that I can not remove completely as they have encrusted large rocks at their bases. <<Different species about (Nudibranchs), but my experience with these critters is they showed a definite preference for the plating (e.g. - M. capricornis) and encrusting (e.g. - M. danae) Montipora over the branching varieties>> Just yesterday I noticed 1 Nudi at the base of one of these colonies (Where there is one, I'm sure there are more). <<Yes>> After dispatching this Nudi I inspected as best I could and can not see any more. <<Again, in my experience, once the food source is removed they tend to "disappear" quickly>> So having found this in my display still and not being able to easily remove all of the Montipora, is there a fish predator for these guys that would make an appropriate addition to a community reef tank for a 90gal? <<Not that I'm aware...for sure. Some of the reef-safe wrasses "may" eat the Nudibranchs, but I have never witnessed/heard confirmed reports of this. If you wish to try, a wrasse from the genus Halichoeres might be a good choice>> I have seen a couple of species or wrasses mention, but little direct discussion. <<Indeed...I once experienced and episode with these Nudibranchs...I had wrasses from four different genera in my tank (including Halichoeres) but could never discern any of them feeding on the Nudibranchs>> Thank you, Stephen <<Quite welcome, EricR>>

Nudibranchs/Ceratosoma tenue 5/15/06 Hi Crew, <Hello Mohamed> This weekend I found 10 Nudibranchs which looks like the Ceratosoma tenue on the site. All my new corals are dipped before placing in my display tank. At the time of removing some sick corals for a dip, I found the Nudibranchs which I removed but yet all the corals did not survive. I would assume that the Nudibranchs was feeding on the corals. I am sure there are more. I have used a trap but have not caught any as yet. Is there a fish, invert, etc that can be used to feed on the Nudibranchs but must be reef safe. <None that I know of due to the fact of their nasty taste. Bob may know of a predator and hopefully inject something here. <<Nothing specific. RMF>> Most Nudi's are carnivores and each species usually has a particular victim. Victims are immobile invertebrates such as barnacles, Zoanthids, anemones, hard corals, etc. I'd pluck them out by hand to be on the safe side.> <<Or siphon out. RMF>> Thanks <You're welcome. James (Salty Dog)> Mohamed.

Nudibranch/Phyllodesmium briareum/Compatibility 3/30/06 I have a Phyllodesmium briareum Nudibranch, identified by LFS. It is living in/eating my green star polyps. My question is will this type slug harm other corals? <Does feed on soft corals in nature. I would return as eventually all your star polyps will be eaten.> I also have many SPS species, Toadstool leathers, Candycane, frogspawn and a torch coral. The GSP are spreading rapidly except where the Nudi is currently. Thanks <You're welcome. James (Salty Dog)> Mike Winston

Re: Phyllodesmium briareum - 4/11/2006 Thanks for the reply, <You're welcome.> I did not get from your reply if this type of Nudi is a threat to Frogspawn or torch coral. It is really an interesting animal and so far I have seen no harm to anything other than the GSP but have not found any real descriptions of what exactly is meant by "Soft Coral", Could the polyps of the frogspawn be considered? <Soft corals do not have a calcium base, attach/grow on rock. I don't have a specific on exactly which soft corals they consume. If you wish to keep the Nudi, your Green Star Polyps will be at risk and once these are gone, the Nudi may seek other items on the menu. You will just have to monitor the situation.> Thanks again <You're welcome. James (Salty Dog)> Mike

Chromodoris willani...is this Nudibranch toxic at all? 8/19/05 thanks Danielle <Mmm, yes... unpalatability is a clue, eh? Bob Fenner>

Re: Chromodoris willani 8/22/05 Hi About the Chromodoris willani, I guess I should be more specific, if it dies will it poison my tank? Sorry for being so vague earlier. Thanks Danielle Workman <Still too vague... if the tank is large enough, well-filtered, circulated... no problem/s. Bob Fenner>

Phyllodesmium Munched Xenia? - 06/18/05 Greetings. <<Hello>> I have a 30 gallon saltwater tank with 10 gallon sump. A protein skimmer (Excalibur) resides in the sump along with the heater. I have about 30 lbs of Tonga live rock, with two cleaner shrimps, 5 hermit crabs, a toadstool leather coral, a green star polyp colony, one (individual) green Ricordea mushroom polyp and (most recent addition) a "Pom Pom" xenia colony. The aquarium is about 2 months old. Water parameters are: Temp=78-80, ammonia/nitrite=0, nitrate<10, dKH=12, ph=8.0. Lighting is by Coralife power compacts (96 watt 10K daylight and 96 watt actinic). <<OK>> My primary question is about the Xenia. It was a beautiful specimen when purchased one week ago at the LFS. Two days ago it started to "shrivel" and exhibit a small amount of "slime". This condition worsened and this morning, before daylight, I observed it with a flashlight. I saw what appeared to be a portion of the colony moving down the live rock below the main colony! When I realized it must be a Nudibranch, I removed it. <<Good move.>> It excreted a clear, gelatinous substance when it realized it was detected. I did a search on the internet and found something called a "Phyllodesmium", a Xenia eating Nudibranch, which matched the appearance. The Xenias shriveled to less than 1/2 its original volume, but most of it is still pulsing. What can I do, if anything, to save this beautiful creature? <<With the removal of the Nudibranch (though do check for more), tis likely the Xenia will recover...though a dose of iodine (follow instructions carefully) may help.>> In the case of its tank mates (other than the Nudibranch!), the LFS was aware of everything in the tank and I basically have followed their recommendations when selecting from among creatures that appeal to me, since they seemed fairly respectable. I now know, after researching your site, that the ph should be > 8.3 for Xenia. <<Yes...and as stable as possible.>> How quickly should I increase the ph from the current 8.0? <<Over the course of a couple days will be fine.>> A secondary question concerns the coloration of the green star polyp colony and Ricordea. Both have turned a lighter, more yellow-green since being in my tank. The Ricordea is near the substrate, while the green star polyp is near the top of the tank. Do you have any suggestions, or is this normal? <<You have them placed as I would suggest. Coral coloration is as much a function of feeding as environment. If you are providing good water flow (minimum 10x tank volume.), try feeding a bit if finely minced meaty foods to the corals. Frozen Cyclop-eeze and Sweetwater Plankton are great foods for this.>> The size of the Ricordea is the same or slightly larger than when purchased, although the green star polyps don't seem to extend quite as far as they first did (perhaps due to crabs crawling on them?) <<More likely inadequate water flow.>> With great appreciation and respect, Lan Carter <<Warm Regards, Eric R.>>

Predatory Nudibranch? Hi Guys, I'm fairly new to reefing. <Welcome! Ryan with you> I've had my tank for about 6 months ....I recently purchased a yellow leather coral and about a week ago I noticed it has acquired a small host (about one inch). I'd like to know what it is and if it is beneficial or harmful. <Likely harmful...Everything on a reef eats something else on the reef. Perhaps send a picture, but I'd remove it ASAP if it was me.> It appears to be some form of Nudibranch and it stays solely on the yellow leather. Its color is bright white with black specks on it. the black specs are located mainly on its sides and lower area. I'd appreciate any information you may have. Thank you for your help. Rick. <Sounds predatory. These are fairly common with new acquisitions...Read up on quarantine procedures. Good luck with the removal. Ryan>

Nudibranchs in tank. I have a question about an unknown hitchhiker that has shown up in my 12gl Nano Reef tank. <Good Morning Julian, MacL here with you.> I believe that it came in on some star polyps. <Just one quick suggestion Julian and that is to quarantine your corals or at the very least dip them.> I have other corals and a tube anemone but the star polyps seem to be the most likely to harbor small critters. <I do understand what you are saying with this.> It is reminiscent of a small transparent brown Nudibranch with red points on it's tail end. It looks similar to the symbol shown below. The largest of them are around 1 to 2 mm square in size and really thin (transparent. They appear to be eating algae but I'm concerned that they might be or might start eating coral flesh. <I had a short episode with these guys in my refugium. They were a pain to get rid of but eventually I did it. First, they went out of control because my tank was out of balance so water changes helped that immensely. Then I had to cut drastically back on the lighting in my tank. While they seemed to feed on algae, they seemed to need the lighting to flourish.> They are breeding like pink tribbles. <Definitely! I also sucked them out of my tank with a turkey baster.> Currently the only mobile predators in the tank are a fire shrimp, arrow crab and a citron clown goby. They don't seem to be interested in munching on them. Part of me wonders if they will eventually level their numbers out over time and evolution of the tank...But...I just don't know. Do you got any suggestions or words of wisdom to share? <I think that you could add some type of Dottyback or wrasse to munch on them but if you do the things I have suggested you should be able to get rid of them shortly. Took me a little over a week to see a difference. Good luck, MacL> Thanks a bunch and have a wonderful day

Phyllodesmium ate xenia Hello. I tried to send an e-mail yesterday by going to your website, but perhaps it did not make it through. I have a Pom Pom xenia, which was really a beautiful creature when purchased a week ago. Three days ago I noticed it "shriveling up". I inspected it during the night and found what appeared to be part of the colony moving down the rock away from the rest! It turned out to be a Phyllodesmium that had been eating the xenia. <Collected and shipped with it> I removed the Phyllo., which secreted a gluey, clear coating as I removed it from its hiding place. Inspecting the xenia afterwards, I could see that the damaged areas were whiter than the rest. I trimmed what I could of the damage away from the rest of the colony. Is there anything else I can do to help save this beautiful creature? <Mmm, not much that I know... perhaps a full-dose of iodine/ide will help. Will ask Anthony Calfo, an old culturist of Xeniids, for his input here> The remaining colonies are still pulsing but are also shriveled, although not discolored. Tank details follow: 30 gallon with 10 gallon sump, Excalibur protein skimmer, Coralife 192 watt power compact lights (half 10K daylight, half actinic), ammonia/nitrite=0, nitrate<10, dKH about 12-13, ph 8.0, salinity 1.024. The tank has been running about 2 months. I am slowly raising the ph using SeaChem's marine buffer 8.3 (supposedly reaches 8.3 and holds there). I am adding, daily, about 1/3 the amount of the buffer that the bottle recommends (just trying to be cautious). Tank inhabitants are: 2 cleaner shrimps, toadstool leather, green button polyp colony, 1 Ricordea mushroom polyp, 30 lbs Tonga live rock. Any suggestions would be appreciated. Thanks, Lan <Keep your eyes open for other Nudibranch predators... Bob Fenner>

Whodunit? I have a 75-gallon, 6-month old reef with a light fish load and mostly corals and clean-up crew. Recently two Nudibranchs (or so I am told) came in on a colt coral. The coral died, the unexpected guests grew bigger. They were white, about 2 inches long, tentacles like snails, with white lacey, almost "fluffy" bodies. Beautiful! I have seen similar, larger ones for sale from a local livestock dealer. After a large mushroom colony that had been thriving suddenly crashed (everything else in tank is fine) I became suspicious, and removed the creatures. I know that it is not known for sure what Nudibranchs eat -- is it possible they ate the colt and mushrooms? I have a cowry in my reef, as well. It is exquisite, and stays on the glass or substrate much of the time, but occasionally can be found on corals (knocking over the live rock is a problem). I consulted The Conscientious Marine Aquarist, and found no indication that they may eat my soft corals. Could the cowry be the culprit? Did I remove the wrong tank inhabitants? One other question -- my phosphates and nitrates have been consistently high lately, so I added a Poly Filter just last night. In addition, I added "d*nitrate" over the weekend. I was told these would be okay together in the sump. Do I discontinue adding supplements? I usually add Coral Vital and C-Balance every other day, and Strontium and Iodine once a week. I have beautiful coralline algae growth that has taken months to begin developing. I hate to sacrifice the growth process. Please advise! Thank you, Margaret Camp >> Thank you for writing. I do strongly suspect the Nudibranchs. Yes, there are "naked gill" snails as you describe, that have soft coral diets... and they can be destructive. Of the couple hundred species of Cowries (family Cypraeidae) I am familiar with a few that will eat some soft corals... but not as you relate (have some friends of friends in the shell interest who have me looking for a handful of species on foreign travels... for science-karyotyping... so have more than a tangential interest in the group). The cowry would not consume the leathers like this... The PolyFilter should be fine, with or without the other product, and I would continue with your supplement routine... and increase water changes, boost lighting to "use up" the excess nitrates... Is there any way to convince you to consider making a denitrator in the sump? Even just adding a couple of units of Siporax beads there will significantly reduce the NO3. Bob Fenner

Fin Rot? My husband has a 50 gallon saltwater tank. Up until about 3 days ago, he had a black and green Nudibranch in the tank. Unfortunately, this poor creature met his demise when he got sucked into the power head. I'm not sure how long he was stuck in the powerhead, but I came home and noticed that everything did not "look right" with the tank. That is when we found the Nudibranch and promptly removed him. At the time that we found him, we also noticed that all of the fish were stressed and covered with what looked like freshwater aquarium "ick." There are two blue/yellow damsels, one domino damsel, one yellow tang, and a clown fish in the tank. At first, the domino damsel seemed to have suffered the most. His fins were tattered and bloody and he had a white "covering" on his eyes. Soon after, the clown fish and one of the blue/yellow damsels were affected. The tang developed clear, blister-like nodules on his fins (excluding the tail and dorsal fins). We have done a 25% water change and yet the "fin rot" seems to be getting worse. The tang now has no flesh to speak of on his fins...there is nothing left but bone...and his dorsal fin and tail are showing signs of infection. My first thought was that the Nudibranch released a "poison" into the tank when he was chewed up by the powerhead. Am I correct? If so, what action and/or treatment can be done to clear this up before all of the fish are affected and killed? The biggest problem is that my husband also has anemones, tube worms, sponges, soft corals, and other invertebrates in the tank. Whatever is in the water seems to be affecting EVERYTHING and we don't have a hospital tank. PLEASE help us...give us some advice...something to try! Thanks, Gina and Dane Gerdes >> How much made-up synthetic seawater do you have on hand... Change ALL or as much of the water as can be removed and replaced to have all your gear still working (i.e., if only half the tank can be refilled, but all your filters, pumps, heaters work, do so). Do you have any chemical filtrants like activated carbon on hand. Do place that in your filter flow paths... You've noticed how distinctive Nudibranchs are in "wild" photographs? And how slow moving they are in captivity? Yes they are bundles of noxious materials... as part of their involved defense mechanisms package... Here's hoping that the massive dilution and absorption saves the rest of your livestock. Good luck to you. Bob Fenner

Nudibranch I was wondering if you thought that a 1 inch long white with black spots, slug shaped Nudi a white bush structure on his back was bad for a reef tank? <In your ninety gallon system with lots of live rock? I'd leave it. Likely no problem if it lives or goes.> I see him on the glass every morning. <Watch him while you're sipping your AM Joe> He came on the Marshall Islands live rock that was extra fresh. Thank you as always, Todd Gabriel <Be chatting. Bob Fenner>

Re: Nudibranch Actually I have caught three of these little Nudi's last night I isolated them in a plastic bowl floating on top of the tank. Will tree of these little cuties eat my stony corals and clams? <Rare that Nudibranchs might eat stony corals or clams. Prefer other foodstuffs. Bob Fenner> Thanks for the expert advice. Todd

I Need your expertise Hello Robert! <Hello> We've written each other many times this past year. I'm the guy who had Arnold the Octopus! Anyway that's not important. I know I shouldn't impulse buy things without research ing, but I think it got the best of me yesterday. I was just going to LFS to get water and food and 35 dollars later I came home with a Tube Worm, I think its spelled a small Purple Pseudo and Sea Slug. <Okay> The???? is or concern rather is will this Sea Slug eat my Mushroom Corals and Gorgonians. When I asked this ?? at the store the employee said no, it would just sit in an area were their is the most current. <What? Can't tell from your description what this animal is, but this description: "just sit..." is ridiculous> and that is exactly what it's doing as of the last 13hrs. He's moved all but an inch. I wanted to learn more so I found a very small blurb in a Book saying that should it happen on a suitable food source, it will usually be a prized coral which they will feed upon until it is dead. (Showing a pict of a Chromodoris quadricolor) Is this true? Can I stop him before the damage is done, cause he moves so damn slow! Or should he be removed from the tank? My slug is a Hypodoris Bullock I think! Take a Look! http://logos-and-graphics.com/seaslug/HypselodorisBullocki.jpg http://logos-and-graphics.com/seaslug/HypselodorisBullocki2.jpg <Mmm, members of this genus have typically narrow feeding strategies... consuming only a few genera, species of sponges, gorgonians... My pic, input on Nudibranchs... http://www.WetWebMedia.com/nudibran.htm Bob Fenner> Hope you had a great peaceful holiday Thanks JET

Nudibranch on star polyps Bob, First of all, I am grateful for the wealth of information the WWM group provides on a daily basis. I found two Nudibranchs on my star polyps which can be seen while the lights are either on or off. Found a picture of them on the web which labels them as a soft coral eating Nudibranch or Dendronotacean. See following link http://rshimek.com/rogue's_gallery.htm Should I just pull of this pest off with tweezers/wash off ... please advise...I also read in Sprung's Vol. 2 of specific harmless Nudibranchs which co-exist with star polyps .. they looked quite similar in appearance. Please help Thanks again, Joe Velazquez <The link did not come through for Shimek's ID. In general though... predatory Nudis do severe damage fast. If more than a week has gone by... I'm thinking you are likely safe. Do cut and paste or attach a picture if you need to follow up. Best regards, Anthony>

Nudibranch on star polyps Bob, thanks for the reply, pulled both Nudi's off of starpolyps last night with tweezers (they held on for dear life)... polyps have not opened since yesterday morning, hermit crab seemed to be working on polyps this morning ... hope this is the reason for no polyps. <quite possibly... they are tripped easily> Should have taken pictures prior to ... Great to have someone to communicate with about our hobby/passion ... owe you a beer .... Joe <agreed... do look up a local aquarium society as well... perhaps the best place for fellowship and information with enthusiasts> While I have your attention ... any feeling on coral feeding with "Aqualine Plancto". Recommended Feeding daily (roughly 8 drops for 120 gallon reef. Concerned will eventually encounter diatom bloom. <as with any nutritive supplement, experiment judiciously. Maintain regular water changes and good nutrient export processes (skimming, chemical media, water changes) and you will likely be fine. There certainly are no miracle additives out there> thanks again <always welcome, Anthony Calfo>

Coral Slugs eating away I posted a message at 'About Saltwater Aquarium' and was referred to this site ("Try sending the pics over to WetWebMedia.Com and ask Bob Fenner and the boys they might be able to help"). <Anthony Calfo in your service> Anyhow, here's my original post, I hope you guys can help. Thanks in advance! <our great pleasure> "I purchased a Sinularia coral about two weeks ago. It's looked fine for the first few days but then started closing up. I changed it's position in the tank a few times but noticed yesterday that it was getting smaller and portions appeared to be deteriorating. Well, upon closer inspection I saw something eating away at the coral which looks like some sort of slug (I've seen them once before eating my Colt coral). <Correct... the same "Tassled" (cerata) Nudibranch (Dendronotacea)> I pulled out the rock to remove the slug and found a total of SIX, just eating away (coral is about 1/3 to 1/2 of it's original size). Anyhow, I was wondering if anyone here can identify these slugs (or whatever else they might be). <how specifically? Not at all possible by photograph to species... perhaps not even to genus. Suborder given above> Here are the pictures: One last favor / question: I attached a picture of the coral (when it was healthy). When I purchased the coral, the LFS said it was a Sinularia BUT NOT a Finger Leather Coral. I would like to narrow down the identification a bit further. It looks like a Blushing Finger Leather (Cladiella) but I just don't know. Any help would be great." <Hmmm... for the record. The taxonomy has all changed for some of the Alcyoniids. The tall branching colt corals we knew as Cladiella were moved to "Alcyonium" then (now) to Klyxum. Your coral as depicted appears to be a true Sinularia but may in fact be a legitimate Cladiella> Thanks, Onel <best regards, Anthony>

Predatory Nudibranch - 2/11/03 Hi guys, just a quick question for you. Am I right in assuming that the white creature shown in the photo above the cauliflower coral a Nudibranch? <Yes... Tritonia or Tritoniopsis for example> if so is it a species the predates on corals <Yes... it eats soft coral like the one in the picture (soft finger leathers, encrusting colts, Cladiella, etc)... they also breed in aquaria and seem to have direct development (dangerous for your corals). Remove ASAP> as I have two in my reef system that came in with the cauliflower corals. thanks guys Paul <A common hitchhiker on Indonesian imports... indeed, please do remove ASAP. Anthony>

Predatory Nudibranch - 2/11/03 hi Anthony <Howdy> thanks for confirming my hunch about the Nudibranch . <our pleasure> I took both of them out when I got home from work and read your e-mail unfortunately I lost a chunk of cauliflower but without your help it could have been a hell of a lot worse <no worries... all will recover easily in months> I try and keep what hitchhikers I get but these just gave me a bad feeling <agreed... and please be sure to try to catch these by holding all coral in a proper QT for several weeks before entry. This predator was easy controlled in the display... but next time you could suffer something wholly infectious. QT everything wet! that your bring home (plants, algae, coral, fish, etc)> thanks once again Paul <best regards, Anthony>

Nudibranch In Danger? Hello, <Hey there! Scott F. here tonight> First off, let me tell you how much I enjoy your web site. I have been into saltwater tanks for a few years now and I have received lots of great information from your site. Thank you. <Glad to hear that!> Now, here is my problem: I have a 68 gallon reef tank with a wet dry filtration system. Recently I noticed that one of my lettuce leaf Nudibranch was in my wet dry. He seems to be doing fine down there but I want to put him back in my tank. However I am worried about moving him. I have heard that some Nudibranchs are toxic and I wanted to know if this particular species was one of the toxic ones and what the safest way (if any) was to put him back into the tank. <Good question/concern. I have not heard that this one is toxic, but I would operate under the conservative assumption that all of Nudibranchs can be toxic. I would simply carefully remove the animal and deposit it back into your aquarium. No real technique here-just try not to damage the animal.> If you have any suggestions I would appreciate them. John <No great expertise required-just be careful! Good luck! Regards, Scott

Lucky Nudibranch find - 3/31/03 G'day Paul, <G'day mate> Thanks for getting back to me. <No worries> I have managed to track down a picture of my friend the slug. Without a digital camera I was trying to figure out how to get a picture to you and then, lo and behold, I found a web site full of pictures of sea slugs (I even found a recipe for boiled sea slug!- I guess our different tastes and priorities are what makes people interesting) <Especially those of us who know that the Outback steakhouse is not true Australian food> a picture of the slug in question can be found here: http://www.mars.dti.ne.jp/~furuse/watching/SLUG/n3.html its name is: Stylocheilus longicaudus (Quoy & Gaimard 1824) with the cool Japanese name of: kurosuji-amehurashi. You asked if I was sure if he was grazing on the algae growing on the sides of the tank. He sure is, like a horse. When he is on the front glass I can see through to his underside and his mouth is going non-stop while he mows down the algae. You can even see the (algae free) tracks where he has been. <Well, congrats on a very cool find. Now, before I put this guy in my tank (if he were mine) I would just go around to various sites on Nudibranchs, like the one above and http://www.seaslugforum.net/, as well as a great many other sites to be found through your favorite search engine. In any event, I would gather as much information as I can before letting him loose in the tank. Also, send an email to David Behrens of SeaChallengers.com. He does extensive research in the area of Nudibranchs and is a valuable source of information. He may be able to point you in a direction. Let him know Paul Mansur sent you and or Bob Fenner for that matter. He doesn't live far from me and occasionally I get to see some of his presentations. Fascinating stuff. More and more information coming out about the various Nudibranchs all of the time.> Thanks again for spending your time on my question. <My pleasure. Please let me know what you find out and also how your tank does with him in there. You may be on to a new Nudibranch that could be useful to the reef aquaria trade! Paul.> Jeremy.

Reef Safe Nudibranch - 3/28/03 I am very sorry I tried to look this up but either I am looking in the wrong places or I am blind. <No problem> I just want to know if they are reef safe. <Elysia (sometimes referred as Tridachia) crispata are known to be reef safe. Check on the forums at the many reef sites and more importantly check out http://www.seaslugforum.net and http://www.wetwebmedia.com/grnalgcont2.htm Please take the time to learn about the environmental conditions and the specific needs of this useful but delicate animal> My LFS has a real nice looking one and I want it but don't want to loose coral. Any help is appreciated. <No worries. Paul> Shane

C. varians Algae Nudibranch Hey People...how goes it? >>Greetings, Dennis, Marina person here this morning, and it goes quite well, thanks for asking. >I am writing to ask your opinion regarding the Nudibranch C. varians as a way to control the flat worms that are spreading like wild fire in my tank. I have a 150 reef that is littered with the little red devils. Albeit harmless they are an eyesore. Problem is that my LFS never has the Nudibranch and I am forced to purchase them via internet and will be sent to me without a stay alive guarantee. I guess these die easily in transit; moreover, I hear these things die easily period and have a natural short life span. How many do you think I need to eat say 10,000 worms? >>You've presented me with a question I haven't got ready answers for, as I'm unfamiliar. I'll do a search, but off hand I think that it would first be prudent to start with one only, see what happens. Try this article on the flatworms themselves, as there is indeed a real dearth of information on the Nudi you're considering. http://www.wetwebmedia.com/pestflatwrmanthony.htm >>Also, try a search (I'm assuming you've already searched our database for information on the flatworms and the C. varians) on http://www.reefs.org/library -- don't forget to search Advanced Aquarist itself, too. Best of luck to you, Marina.

Nudibranchs vs. amphipods 6/4/03 Thanks for such a great site. I've just spent a relaxing evening hunting Nudibranchs with a wooden kabob spear. <yikes, bub! Resist that habit. There is a thread from a chap on ReefCentral who went into anaphylactic shock over squishing a small Nudibranch with his finger. Any sort of molestation I the aquarium can/is likely to instigate a noxious exudation from this categorically potent family of Mollusks- the Opisthobranchs. Even if you are safe from their poisons, who knows what is being released and harming the other tank inhabitants?> They crawl/stick right on. Better fright value than renting "Alien" at the video store. The small soft coral they were vandalizing (and came with, and I've just learned the hard way about more adequate quarantine) looks happier for being pest-free. Oddly enough, it fell off the rock to which it was attached (lil scalawags ate it from the base!) and now has bloomed nicely on the aquarium floor. I think I nabbed them all, but predictably enough, a pack of Nudibranch eggs scattered behind the rocks as I was eliminating their abusive parents. Is there any hope other tank scavengers may have at them? <many wrasse species indeed. Some angels> I've got a nice throng of amphipods, coral-friendly snails and crabs, various polychaetes, not-yet-plague level Aiptasia, a couple of damsels. Are they any threat to sea slug invasion? <no worries... the slugs are generally prey-specific. You may want to remove that coral for a month to try to interrupt any direct development of more slugs> Are any tank dwellers a natural threat to them? Thanks very much. <not as many as we would hope... getting back to their potent toxicity. Perhaps just removal of the coral and spying for the next month for stragglers. Best regards, Anthony>

Lettuce Nudi (8-9-03) Hey guys,<Howdy, Cody here today.> I was wondering, I'm getting a lettuce Nudibranch. I have 2 tangs coral hermits snails coral banded shrimp. I was wondering, I have this algae that not even my tangs will touch, it's too thick; will a Nudibranch be ok with these animals? I have a 75 gallon reef with a protein skimmer and a duel bio wheel and a bunch of power heads <He should be fine, just make sure all powerheads and intakes are covered as they have a tendency to get sucked into them. Cody>Thanks JM

-It doesn't pay to sample a Nudi!- I feel that I know the answer to this but, we just purchased a lettuce Nudibranch and noticed that he had been nipped. The second day there was a little piece of him on the substrate but he was still moving along just fine. By the evening our Sailfin tang was dead and by the next morning our very large yellow tang was also dead. <The two most interested in an algae meal...> My assumption is that these are the two fish that nipped at the Nudibranch. <Likely, the thing does look like a tasty clump of algae.> I have removed our new addition. Is there anything I need to do other than a water change to help protect the other fish? <I would add new/replace activated carbon in the tank and do a small water change for good measure.> As I mentioned, the Nudibranch was still alive. Thanks for your help. <Good luck! -Kevin> KatMcD

Nudibranch assistance Thanks for great website. <Thank you Chris for the compliment, MacL here with you tonight> I found few opisthobranchs on my reef they were around my expensive blue zoos and pink zoos I removed 3 of them yesterday night but is there any better way than wait for them to show up and catch them? <Youch that's a big problem. Honestly I have heard there are traps but I've never seen any that truly work other than just pulling them off. Also I have friends who isolate their zoos to try to catch them. Usually they show up more at night so with a flashlight and/or with a red-light?> One of them were on my orange zoos and it's some tassels color was orange I am sure it is eating my zoos (Some reason starting 3 weeks ago all of my zoos are not doing good (all other corals are ok) I could not figure out why but now I know...) <They can be terrible problems. let me also recommend you look on www.seaslugforum.com> Since my camera is not so good it looks like this http://www.wetwebmedia.com/nudifaqs.htm Nudibranch id 6/11/03 Thanks Chris Kim

Brittle star eating Nudibranchs Mr. Blundell, << Please no Mr. Just Blundell, or Adam or hey you >> While I am thankful for your advice & experience, I have to inform you that I have caught my culprit in the act of attempted lettucide-- it was my spiny brittle star. << Seriously? Really? >> I was watching my remaining Nudibranch on one of the live rocks, & noticed that he was inching his way closer toward the brittle star. I allowed this for a few minutes to see what would unfold. The brittle star's arms were feeling around the Nudibranchs general vicinity, & at 1st I didn't think anything would happen because when he touched the Nudibranch it would seemingly recoil away. Despite this, however, his arms kept returning & touching the Nudibranch. << Not too surprising, but if ends up eating him I'll be surprised. I'm reading your email with suspense. >> I was then distracted by the phone, & left the tank for only a minute, but then I returned, the brittle was all over the Nudibranch. He had pulled it down from where it was munching algae, & had completed wrapped his arms all around it. << Well that indeed sounds like he is eating them. >> I was able to remove the brittle from the Nudibranch, & although it had secreted a large amount of mucous, seemed more or less alright. I temporarily relocated him to my refugium, where he did fine for the night & following day. << That is surprising, after being munched on. >> The following day, I traded in my brittle for a new Nudibranch. Even my LFS was surprised, but not too much so. My thinking is that brittles are scavengers, & scavengers are typically opportunists in nature & cannot pass up an easily caught meal. << True, but Nudibranch aren't the most tasty food for them. >> I'm also thinking that Crispata, not being true Nudibranchs, may not have the same toxicity as true Nudibranchs. << Could be so. >> They seem to have more of a camouflage coloration than the bright, "leave me alone, I'm toxic!" warning colors as well. << True. Want to sound smart. We call those "aposomatic" colors. Use that in a sentence with your friends and you'll sound really smart.... or really nerdy. >> Thank you anyway for your response, & I hope that you can benefit from my experience as I most certainly have from WWM Crew's as well. << Indeed, I know what to answer next time I receive this same question. Thanks for your input. >> Take Care, Pete << Blundell >> > My 1st suspect is the brittle star-- I'm thinking that with his long searching arms it may have come across it & probably could have caught it pretty easily. I don't think this guy is actively predacious, but could > be opportunistic? << Doubtful. I wouldn't think of him as the problem. >>

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