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FAQs about Sea Slugs, the Opisthobranchs, Disease/Health  

Related Articles: Sea Slugs, Nudibranchs,

Related FAQs: Seaslugs 1, Seaslugs 2, & FAQs on:  Seaslug Identification, Seaslug Behavior, Seaslug Compatibility, Seaslug Selection, Seaslug Systems, Seaslug Feeding, Seaslug Reproduction, & Marine Snails 1Marine Snails 2Marine Snails 3 Nudibranchs, Nudibranchs 2, Nudibranch Identification, Nudibranch Behavior, Nudibranch Compatibility, Nudibranch Selection, Nudibranch Systems, Nudibranch Feeding, Nudibranch Disease, Nudibranch Reproduction, Berghia Nudibranchs, Snail ID 1, Snail ID 2, Snail ID 3

Lettuce Sea Slug with Bubble on Back  4/15/09
Good Morning,
As so many have done before me, I'd like to thank all of you for your generosity in sharing your time and knowledge to help us make more informed decisions as we build our reefs. I cannot begin to tell you
how valuable it is to beginners such as ourselves to be let in on the complicated problem solving that maintaining a healthy aquarium requires.
<Welcome and thank you>
I have attached two photos showing the back of our Lettuce Sea Slug, as s/he seems to have a smooth bubble or bump that we have been unable to identify visiting the Sea Slug forum. We are hoping you might help.
<Not on: http://www.seaslugforum.net/!? I would send the image and question to Dr. Rudman directly>
Our reef is 36 gallons with a refugium. It is an open top layout, and is wider (24x24) than deep (14) with LED lighting. The current residents, in addition to the Lettuce Sea Slug, are 2 Picasso clowns, 2 cleaner shrimps, 3 glass shrimps, one fire shrimp, one fighting conch, one blue-legged hermit crab, one Margarita snail, one Turbo snail, and one tiny, uninvited crab we are trying to catch (<.5", perhaps a Gorilla), and an assortment of corals (about 9 at this time). Our test values are 1.025 salinity, 0 nitrite, 0 nitrates, 8.0 ph, .025 phosphate, Mag 1330, and CA about 450. The tank inhabitants, including the Lettuce Sea Slug, seem active, curious, and 'happy' and all eat readily.
Thanks for any identification of this you may be able to suggest as to whether or not this is: normal-not to worry, unusual-not to worry, a parasite-start worrying (and you might do this . . ., etc). We do have
a QT tank set up and ready to go should we need to use it.
<I have noted such "vesicles" in wild and captive Elysia (though I don't know what they portend)... and do think this is nothing to worry re. Bob Fenner>

Re: Lettuce Sea Slug with Bubble on Back  4/15/09
Thanks so much for your reply.
<Welcome Lianne>
I actually had attempted to email Dr. Rudman, but the SSF is not accepting messages, saying he is "out of town through the month of January, and will not be accepting messages again until February."
Not quite sure what this means, as here we are in April, but perhaps he is on leave until next year.
<Am surprised that he/Bill has not noted the extreme drop-off in his correspondence... I will try to send him a note in another way re>
So I really appreciate your prompt explanation.
<Welcome. BobF>

Shrinking Lettuce Nudibranch  12/8/08 Hello WWM Crew, I purchased a Lettuce Nudibranch about a week ago to take care of some small patches of hair algae that won't go away. <Mmm, this, and other "algae eaters" don't "eat all" types of algae... Very often one encounters what you detail here...> It stayed on one rock for a couple of days and then started to cruse the tank (200 gallon reef). I woke up this morning to just the head which it is still alive and continues to move about the rock work. I haven't been able to find any information on whether this is normal or not... or if something in my tank caused this (Overflow, Crab or Fish). Thanks Nick <Mmm... could be a predator... or the gear as you suggest... In this size/volume system I'd leave it be... hope for the best, see if it regenerates... As to the algae, I'd seek other means (competition, nutrient deprivation...). Perhaps a cursory read here: http://wetwebmedia.com/algaeasfriend.htm and the linked files above... Your system, from your excellent photos, seems to be very healthy... just a bit more nutrient rich perhaps than it should be... Increasing RedOx here, in a few possible ways, might be the window/avenue to pursue. Bob Fenner>

Re: Shrinking Lettuce Nudibranch   12/10/08 Thanks for the info Bob... I think it may of been my Rancor sized Emerald crab, the Nudi does look like a taste patch of algae. <Yikes! Those Mithraculus (nee Mithrax) crabs are definitely not strict vegetarians... less so with size/growth!> As far as my RedOx my ORP is reading at 321, <Ah, right about right... Am just finishing a written pc. that I hope to make into a ppt presentation on ozone use w/ marine systems...> I try to keep it in the low 300s because of the invertebrates. The rest of my levels are reading 0 beside nitrates @ 10ppm which I am assuming is higher but not showing because of the algae. I have a 20G gravity refugium housing some Chaeto, mangroves and some kind of Caulerpa fed by my return pump but the algae is growing rather slow. I started a water changing routine to see if I can get the nitrates down but so far they are not going bellow 10ppm broken test maybe??? Nick <I do think, judging simply by your photos and able description here, that you likely do have about this much Nitrate... and further... that it's likely no big deal. I would... keep doing about what you have been! Bob Fenner>

Hair algae and pistol shrimp aggression towards sea hare? Hello, I was wondering if you can offer some guidance. Before I begin, my tank info is as follows: 29g Nano reef (running 1 year); approx. 25 lbs. live rock; 5g RO water changes every 7-10 days pH 8.3/salinity 1.024/iodine 420/calcium .06 ammonia/nitrite/nitrate/phosphate = 0 water temp. fluctuates between 80-84° Corals: trumpet coral, toadstool leather (2), branching frogspawn, cluster of xenia, Ricordea florida 5 polyps, asst'd. Zoanthids (approx 6-8? wide cluster) Livestock: 1 percula clown, 1 yellow watchman goby, 1 Rainford's goby, 2 pistol shrimp, 2 lettuce Nudibranchs, 1 dwarf sea hare (deceased) Over the past few months, I've been battling a problem with hair algae covering the live rock and back wall of the tank. Some of the Zoas are starting to get suffocated by the stuff. I've tried blue leg hermits, Mithrax crabs, and Cerith, Astrea, and Mexican turbo snails at different points in time. The crabs hardly made a dent. With regard to the snails, they've all been extremely lethargic following acclimation (hardly moving around), then slowly die off. I took a water sample to my LFS to see if they could give me any clues. Their results were similar to mine above, and their only guess was that the water temperature could be a cause of the snail deaths. <Your nutrients are likely measuring 0s *because* of the hair algae growth. They are consuming them. As for the snail deaths, how did you acclimate them? These animals are very sensitive to changing water conditions (even more so than fish and corals). Please see here: http://www.wetwebmedia.com/snaildisfaqs.htm> I bought 2 lettuce Nudibranchs to help cut down the algae, but have had similar results as with the crabs. Then I was told by the LFS that sea hares were better for consuming hair algae. I bought one and for several days it seemed to be doing well, constantly scouring the live rock. One evening, however, I couldn't find it. After searching with a flashlight, I saw it in the back of a rock cave in the clutches of one of the pistol shrimp, which was going at it with its smaller pincers. I scooped up the alive but injured sea hare and tried to place it high on the glass, away from the shrimp, but it was too weak to stick. I submerged a perforated container and placed him inside so the shrimp couldn't get it. But by the next morning, it was dead. <A lot of the sea hares sold to the hobby are cold water animals that don't live long in tropical tanks. Please see here: http://www.wetwebmedia.com/seaslugsel.htm> The tank gets fed daily, and I often see the pistol shrimp come out to snatch flakes from the water column, so I don't believe they're malnourished. Your answers to other pistol shrimp FAQs on your website state that predatory behavior by pistol shrimps towards snails and crabs isn't uncommon. I read somewhere else that sea slugs and Nudibranchs taste bad, so they usually get left alone by predators. Your thoughts? <They might not all taste bad.> The lettuce Nudibranchs are unmolested and seem healthy, one even laying eggs often. Although I like the interaction of the watchman goby with the pistol shrimp, I'm inclined to trap the shrimp and remove them. <Hmm, I would not remove the shrimp in hopes of saving the sea hare. And I would not seek to solve this hair algae problem with invertebrate herbivores. Please see here: http://www.wetwebmedia.com/algaeconMar.htm> I really want to get this hair algae problem under control. Any suggestions? <Please see the link above.> Thanks, Chris <Best, Sara M

Re: Hair algae and pistol shrimp aggression towards sea hare? 4/30/08 Sara, Thank you for your prompt reply. To respond to your follow-up questions: 1. A few posts within the FAQ on snails (that you referred to me) mentioned magnesium toxicity/overdose as a possible cause of snail death. One suggested poor quality salt mixes could be a source of high magnesium. Would ?Instant Ocean Salt? be considered acceptable quality in your opinion? <Usually, yes, but if you are having problems, you should measure the magnesium and consider trying a different salt (such as Reef Crystals, made by the same company, but generally a better salt)> With the exception of occasional doses of iodine (levels tested periodically), no other additives are put into the tank. Could anything else be the cause of elevated magnesium levels, based on the info provided? <Hmm, not that I can think of...> 2. The snails were acclimated by floating the plastic shipping bag in display tank (I acknowledge that using a QT is preferable, and admit I do not have one) in which they were shipped for 15-20 minutes, then opening the bag and pouring ½ oz. or so of tank water into the bag every 5 minutes until full, then discarding half of the water in the bag and repeating the cycle until bag is full again. Final step is placing the snails in the tank and discarding the bag along with the water inside. Total acclimation time is around 1 ½ hrs. In the same snail FAQ, there was a post where you suggested an acclimation method involving a bowl and wet paper towel; or in the alternative, placing the snail on the glass side of the tank above the water level, allowing it to lower itself into the water at its own pace. Do you suggest I use this method? <IMO, It's worth a try for future snails.> 3. If the sea hare was a cold water creature and the 80-84 degree water temperature was the cause of death - as opposed to predation - isn't it more likely it would have acted sick or lethargic from the start? The sea hare was active and seemed to be eating, scouring the rock and glass during the 5 days before I caught the pistol shrimp clawing? it. <It's hard to say. It could have been solely the shrimp's fault. But all the same, the slug would have likely begun to decline anyway.> 4. I read the algae control article you referred to me. The control methods outlined several factors, one of which was the amount of nutrients in the water. My existing 3 fish get fed flake 1x/day (food totally eaten in under 1 minute). Also, I do 5g RO water changes every 7-10 days. Is the above routine ok? <Normally, yes, but you have a problem...so, something needs to change. Your tank might be overstocked. Nano tanks can be especially touchy in this respect.> Water flow is handled by the ?stock? Bio Cube 29 pump, plus an additional in-tank powerhead. Lighting is by one actinic and one 10000k (72w total, bulbs replaced every 6-9 mo.) running between 9:30 a.m. and 5:30 p.m. daily. Would modifying this routine help combat the algae without affecting the corals? Mr. Fenner's article indicates that most runaway algae problems are due to excess heat and temperature fluctuations. I would hope to find a solution to the problem without spending several hundred dollars for a chiller or via higher monthly a/c bills. <If your temp is staying between 80-83F, that should be ok.> As mentioned, my water temp. is currently hovering near that upper threshold. Your thoughts? <I don't think this is a temp. problem as much as a nutrient control problem. Again, these things are all more difficult to deal with in small volumes.> Current filtration methods include live rock for biological, protein skimmer, bag of carbon/Purigen, and regular weekly cleaning of the filter pads of particulate buildup. The only other control methods are regular brushing/plucking/turkey basting of the rock and back wall of the tank. <I hate to have to tell you this, but if this just a little hair algae, you might just have to "deal with it." Algae is a part of the ecosystem in "real life." Changing salt mixes *might* help with the algae too...you never know.> Thank you again for your guidance, Chris <De nada and good luck, Sara M.>

Sea Hare death(s)  04/14/2008 Thank you for a wonderful site. I apologize for asking a question when I'm sure the information I'm looking for is already posted but I seem to be handicapped in search engines as they always seem to return matches where every single word is accurate, yet somehow out of context. <Ah, yes... GIGO... a need/arena for learning the field/terms, use of Boolean logic... as it applies to such searching perhaps> I have a 90 gallon marine tank FOWLR containing a Yellow Tang, Blue Tang, Coral Beauty, Six line Wrasse, 2 percula Clowns and 3 blue/green Chromis. I started seeing string hair algae of the kind no fish eats (naturally) and by the time I recognized I had a "problem" rather than a simple "event" the algae had taken a pretty strong hold. I corrected the problem (phosphates and a bit of overfeeding) but the algae remained. On the advice of a local pet store I purchased two sea hares <Mmm, what species? Too often cold-water species are offered...> and they went to work immediately! Not only were they in the process of cleaning the tank nicely but I've decided that they are at LEAST as interesting as any fish, so I was looking forward to a long an happy relationship. I came home from work one day to find one of them dead .... with a huge split right up the center of his back, all the way from the vent hole to the neck. Without a picture the best way I could describe it would be if you could imagine a pressure split along the seam of a plastic bag as opposed to any sort of gash from an attach or contact damage. I took him back to the store to see if they could explain what went wrong and they said ... stop me if you've heard this before ... they've never seen that before, never heard of that before, can't imagine any animal or event that caused that and would I like to buy a replacement? <Mmmm...> (um ... not at this time, thank you). Two weeks later the remaining Hare was busy at work at 10 am and dead of the same cause at 2pm. The precision of the split (no rough edges at all) and the symmetry of it (right down the center of the back) as if sliced with a scalpel are very troubling. Do you have any suggestions? Thank you, Gil (not a pun!) <A need for a ready identification. Please read here: http://wetwebmedia.com/seaslugid.htm I suspect you have/had non-tropical species... that don't live in warm settings. Bob Fenner>

Dead sea hare problem?  -01/30/08 I have a large sea hare and I think it might have died because I have not seen it in about 3 days. Here is the real kicker the tank at this point no reaction as far as water quality. <It's possible it's not dead, possible it is dead but simply not toxic... maybe consumed by something else... hard to say.> Should I wait a while and give him a chance to show him self or should I go and look for him. <That's really up to you, but I would. Sara M.>

Several reef questions-LTA, Sea Hare, etc... pre-eminent crash, reading, reading and understanding   01/22/2008 Hello WWM Crew, This is the first time I've asked a question and I must apologize up front, but this may be a long email. <No worries. Take your time> I'm sending a link with photos of my tank for you information. Before I ask my questions, I will tell you about the tank. It is a 34 gallon Red Sea Max system. We purchased it from our LFS on their recommendation. <What do you think of this (new) product? Craftsmanship? Value?> We now know it is more difficult to keep a smaller tank and we plan on moving in 6 months, at which time we will be getting a much larger tank. In the meantime, we need some advice on how to best care for our little creatures. In the tank we currently have two Ocellaris Clowns (one male and one female), yellow-tail Damselfish, Pajama Cardinal, 4-5 Nassarius snails, 3 small turbo snails, 1 fire/cleaner shrimp, Sandsifting starfish, Blue Tuxedo Sea Urchin, Sea Hare (that I've been unable to accurately identify), <Mmmm> Long Tentacle Anemone, <Yikes...> 1 mid-size red legged hermit crab, 3 smaller red-legged hermits, 1 very small emerald crab, a green star polyp coral, 2 very small sea mushroom coral (one of which is attached to what I was told to be "leather finger"), 2 other small soft corals that I can't seem to remember the name of at the moment but I believe to be pineapple/brain coral, and another Favites coral that is not in any photos because we just purchased it. According to yesterday's tests, water quality as follows: Temp: 78 Specific Gravity: 1.023-1.024 Calcium: 460 PH: 8.2 Phosphate: .1 Ammonia: 0-.15 <I do hope this is an anomalous reading... test kit artifact. This needs to be zero> Nitrate: 0 Nitrite: .05. <Ditto> We are aware that we need excellent water quality but we were told by our LFS that our levels were fine for us and we've NEVER had Ammonia at 0. Oh, the tank is fairly new, started in late October 2007. OK, so on to my questions. When we first put the LTA in our tank 2 weeks ago, we placed in where it is located in the photos and it remained there for a little over a week. Just the other day it began to move about. <An "unhappy" behavior> I looked up how to help it settle and tried moving it to a location and feeding it 1/2 of a Silverside. <...> It stayed there for 2 days and then began to roam again. I did the same thing again and it stayed for only 1/2 day and not it's roaming around again. I know that an unattached anemone is an unhappy anemone but I can't understand what more I need to do to help it find a home. <The other cnidarians... the Polyps, Corallimorphs...> When I found it yesterday morning it was sucked onto the sea urchin and I moved it because I didn't think that was a particularly good thing. I thought maybe our substrate wasn't appropriate but the LFS assures me it's fine. How long should I expect it to roam around the tank? <Not much longer... as it will be dead... perhaps the rest of your livestock with it> Should I right it if it's upside down? <Tentacle side up... and place a "strawberry basket or such over it> Based on the photos, can you recommend an appropriate placement that I could try? <... in looking at this animal, considering your system... I would remove, return it to your LFS. This specimen is very badly bleached (dying from a lack of zooxanthellae... which give it color... and nutrition) and your system does not have sufficient quality or quantity of light to support such an organism... Please read here: http://wetwebmedia.com/macrodoreensis.htm and the linked files above> I'll be getting a net today to try that technique mentioned on your site. It's tentacles are usually out while it's roaming around, is this a sign of good health? <No my friend> Next question: The sea hare that I can't identify fell onto the anemone the other day. <Very bad...> Should I be worried about the anemone stinging it? <Yes... and I suspect this is not a tropical animal... See here: http://wetwebmedia.com/seaslugid.htm re this Aplysia> I moved the sea hare when I saw it. What exactly happens to a marine animal if/when it gets stung by an anemone? <Too much to relate to you here... but is recorded on our site, elsewhere> Will I be able to identify if has happened? <This animal needs to be removed as well... is also mis-placed here> The sea hare was purchased less than a week ago and it's laid eggs on the side of the aquarium walls twice. <Stress... reproducing before it dies...> Should I clean this up or leave it alone (none of the aquarium inhabitants attempted to eat it). <Should be removed> The mushroom coral in the photo was purchased at the same time as the LTA. <...> It was open and appeared happy for several days. We added phytoplankton to the tank <Nothing you list actually eats this...> the day we got it and then forgot to refrigerate it so we didn't add any more until a week ago. It had shriveled up but the opened back up when we added the phytoplankton (which we were told to add 3 times a week). We also have been instructed to add 1 squirt of Arctipods once a week. Now the mushroom is shriveled again and has been for 2 days. Is this normal or is this a sign of bad health? If it's a sign of bad health is there anything I can do to help it? <... my friend... you need to read... And STOP buying "things", livestock...> Two more quick questions and them I'm done, I promise. We don't have an RO/DI filter yet (we won't be able to have one until we move) so we've been using Distilled water in the meantime. Since we've never had super great water quality, is this a contributing factor? <Not much> Is there anything we can to do help get the ammonia to 0 (Oh, I forgot, we add Amquel 1x/week)? <... this may be giving you a false positive...> Besides adding PH 8.2 to the distilled water, should I be doing something else? <Reading> Last question. I now know that our clowns don't naturally host with a LTA but is there a possibility that this might happen? <... reading> Is there anything I can do to help this process (besides a home for the LTA)? I know that they can survive without each other but it would be nice if they would pair, besides, the clowns have taken up residency in the little cave in our tank that was home to the shrimp. Now we hardly see the shrimp because it appears to have been pushed out of it's home by the clowns. It would be nice to be able to give it back it's home. Thank you for you wonderful site. I've learned a lot (much of which has come after making this purchase and had I known better would have made different choices). I've looked on your site for answers to my questions and I often see that you refer people to "read wetwebmedia.com about your question". If you are going to refer me to an article, can you please give me a link or please be very specific about the location of the article because I sometimes have difficulty navigating your site. Thank you, again. http://www.sendpix.com/albums/08012114/2t2jg47po0/ Link to photos of our tank Lynda Hounshell <Read and heed the above... and then, keep reading... Do NOT buy anything more w/o researching for yourself ahead of time. What you have now will very likely "crash" soon... You need to ACT with knowledge... ASAP. Bob Fenner>

Lettuce slug hurt   2/14/07 Hi. I have had a beautiful Lettuce Slug for 3 weeks now in an 29 gallon. <Mmm, not easily kept... esp. in such small volumes> She was doing fine and eating algae. But I noticed last night that her back "flowery" section has a slight tear. She seems to be ok. I have a fire shrimp and a Short Spined brittle star. I don't think the Shrimp would do it. The Starfish? <Both, either could> Or, sometimes the current lifts her up and flies around into she can get hold of a rock or coral. We have lots of rocks and coral? <Maybe... the worst is to get "sucked up" against an intake...> Is she so fragile that that would do it? <Easily> And,  is there anything I can do for her.  I have grown very attached to her and love her as a pet. Any suggestions?  Dana <What little I know is posted on our Opisthobranch areas: http://www.wetwebmedia.com/seaslugsopisthobranchs.htm and the linked files above. Bob Fenner>

Sea hare growth ... no info.   5/4/06 My sea hare has a what I can only describe as a growth on the side of her head, it started off as a little growth but by the evening it has grown really long, part of it is long and thin and the end piece is bulbous and a pale blue green colour she is still alive, any ideas???        Thanks for your help            Ellire <Perhaps a tumor of some sort... I'd be checking your water quality, moving the animal if you have another "clean" system... doing water changes, employing chemical filtrant/s if nothing else. Bob Fenner>

Sea Hare Splitting? 10/23/06 Hi WWM crew, <Hello Ryan> I have a 35 gallon saltwater tank. There is a Coral Beauty, orange star fish, three crabs, and a Sea Hare. I woke up this morning and I saw my Sea Hare's skin splitting down the middle. There was something that looked like a white larva where the skin split. I took out the Sea Hare and moved it to a quarantine tank, because I heard they can kill your other fish when they die. <Indeed.> It hasn't moved around in the quarantine tank so I think it's dead. Do you have any idea of why it did this, or how I can prevent it in the future? <Most Sea Hares, if not all, are very difficult to keep.  Should only be attempted by expert aquarists.  They do not appreciate bright light and are algae grazers.  I'm quite sure none of these conditions exist in your tank.  Try something a little more easier to keep in the future.> Thanks for your reply! <You're welcome.  James (Salty Dog)> Ryan Forsman

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