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FAQs about Nudibranch Identification 4

Related Articles: Nudibranchs, Sea Slugs,

Related FAQs: Nudi ID 1, Nudi ID 2, Nudi ID 3, Nudibranch ID 5, Nudibranch ID 6, Nudibranch ID 7, & Nudibranchs 1, Nudibranchs 2, Berghia Nudibranchs, Nudibranch Behavior, Nudibranch Compatibility, Nudibranch Selection, Nudibranch Systems, Nudibranch Feeding, Nudibranch Disease, Nudibranch Reproduction, & Sea Slugs, Marine Snails 1, Marine Snails 2, Marine Snails 3,

Hitchhiking Aeolid? Help ID Please... 9/23/11
Ahoy There! Alex again... I'll try to keep this one less verbose than the past few...
<Verbosity never an issue>
As Bob suggested, I added a truly deep DSB to my sump when I rebuilt it and have been having virtually no problems since... My nitrates dropped from 80-100+ to down below 20ppm in about a week (the 50gal water change undoubtedly helped but after resting and testing I was shocked at how much difference the new sump makes) and my phosphates are below 0.5ppm (decreased by a full order of magnitude!), so that's all good.
<Ah yes>
As promised, I will send pictures soon; I just want to let it grow in a little and then I'll write an article for the WWM forum. I learned a lot building my own and I am excited to share.
Anyway, while you're thinking about that, think about this (hehheh): I recently discovered a stowaway in my tank! I know, this is all too common on the high (maintenance) seas, but I can't figure out what this guy is. I can tell it is definitely some kind of Nudibranch, probably an Aeolid but for all I know it could just as easily be from the Glaucidae family, and by my guess it is still a juvenile.
<Does appear to be an Aeolid>
It has somewhere around 4-6 pairs of brownish-orange cerata and a milky-white-to-almost-transparent body, and it looks to be just over 0.25" long (not quite a centimeter). I do not have a submersible camera but after many (literally hundreds) attempts I was able to deftly snap a few halfway-decent shots through a magnifying glass and then zoom in on the computer, which is why these chosen few images are still pretty grainy. I wish I could offer better ones. In these pictures, the big fork that looks like rhinophores is actually (I think) a large pair or cerata, and the two pairs of tiny whitish prongs at the anterior end are what I understand to be the rhinophores and oral tentacles (but these are nearly invisible in all but the top-leftmost image).
I am curious not only because it looks so much like an adolescent *Aeolidiella stephanieae*, but because if it's not then I'm concerned it's probably eating the Zoanthid polyp it's been hanging out on for the past two days (shown in the pictures).
<Likely so>
If it is a Berghia-type Nudi,
<Not likely>
then it's a bit ironic since I was considering trying to find some but I chose peppermint shrimp instead (which, by the way, decimated the Aiptasia in my tank in about 4 days... now if they can just survive long enough to clean up the tiny ones that will inevitably sprout soon after...), but I'd also like to know so that I can make a decision one way or another as to whether I should leave the little guy in the tank or give it to one of my FOWLR friends who actually has some Aiptasia for it to eat.
<Maybe the latter, but I would definitely at least remove from here>
I am dubious that it is actually a Berghia though, because not only does it not seem to have a clear activity cycle (it slowly paces around this particular clump of Zoanthids night and day), but also because I feel like there would probably have been more than one with whatever rock this one came in on. I do not know how small juvenile Hermissenda crassida specimens can be... perhaps I have one that is recently past the veliger stage?
<Doubtful to the extreme in captivity... the water moving pumps, mechanical filtration, lack of foodstuffs of use...>
Zoanthids are in that weird Cnidarian nether-region between a hydroid and a coral,
<Mmm, much more toward the latter/Anthozoans>
so it wouldn't surprise me to learn that H. crassida might be eating them, but I also can't tell with certainty that the polyp is being eaten. These Zoanthids are sensitive enough that I find it equally possible they would just close up because they're being crawled on, and I can't distinguish any areas with visible damage. Unfortunately, I don't know the exact species of these Zoa's, so I can't offer much in the way of spotlighting diet preferences to help identify this hitchhiker... I hope this image is small enough to accept. I was trying to retain sufficient
detail in the shots.
As always, your scholarly wisdom is highly valued and graciously accepted.
Oh great gurus, what should I do?
<When in doubt I vac it out; it's a free-for-all! Bob (not Ted) Nugent>

Hitchhiking Aeolid? Help ID Please (amendment) 9/23/11
Sorry to send multiple messages, but I just realized a grievous error in my last note:
I mentioned that possibly my stowaway is a juvenile Hermissenda crassicornis
because I had found a picture of a baby one (possibly misidentified, now that I've looked around more...) that looks very similar to the tiny thing crawling on my Zoanthids. Obviously (to you maybe) that is impossible or at least very unlikely, because H. crassicornis comes from cooler waters than my tropical tank and so is unlikely to have survived long on any rocks from the LFS. But after looking at all the pictures listed under the Family Aeolidiidae on Bill Rudman's Sea Slug Forum species list,
<A fave>
I am still not sure what I've got. The closest match besides Aeolidiella stephanieae might be A. oliviae, with its diet of anemones and maximum size of ~20mm, but the ones pictured are supposedly 12mm long and they have many many times the number of cerata I see on the stowaway, and like the Hermissenda sp. they also seem to be from cooler water.
I will pipette it out of my DT and put it in a jar so I can try to get a better picture.
<Thank you. Plah Bob>

Hitchhiking Aeolid (Better Pix) 9/24/11
Howdy Bob F. Nugent (good to know the 'F' stands for 'Fletch' haha)
<I wish I had the Chevy Chase income, and much more acting ability!>
So taking good pictures of tiny sea slugs with a marginal camera is basically impossible, but after much diligence I was able to get these images. As you can see, the beast has far fewer cerata than *A. oliviae* and actually does have a faint orange stripe down its white back, so perhaps it is closer to being a juvenile *Hermissenda* than I thought (but if that's what it is then supposedly it can get pretty large). I also noticed that the tips of said cerata are indeed whitish-colored, and though none of the blacklighted pictures were worth sending (partly because the camera battery died as I started attempting them), I was able to clearly see green glowing specks within the cerata, which confirms that it *was* eating the Zoanthids (or at least eating their zooxanthellae). I currently have the creature isolated in a little plastic magnifier box. I still have not seen any others in the tank, so I'm not sure how likely it is this one has reproduced; it is probably a loner. It's too bad I can't keep it; sure is purdy.
<Can/could... either suffer some attrition of your Zoas, risk reproduction... or place/keep/feed elsewhere selectively>
Do these shots lend any better clues as to the species, or even whether I'm dealing with an adult specimen versus a juvenile?
<Not really. Per BillR's excellent SSForum, you'll note that there is often a very large range of colours/markings, variations in size/dimensions per species, geographical distribution>
Note the edge of the straight razor placed for size comparison... If I could confirm that it will survive eating more than just Zoa's, then maybe I could put it in my refugium and let it cruise around in there.
<Mmm, most Nudibranchs are quite food-specific... Hence my standard issue of collecting/purchasing ONLY w/ their food organisms>
I doubt it can lay eggs without a partner... Even if it could there's apparently almost no chance that any young would make it through the pumps alive.
<Not likely so>
I still don't know which piece of rock/coral it was stashed on, but at this point it has to have been living in the tank at least a couple of weeks
<Greatly probable>
because I doubt it was hiding on the lawnmower blenny I bought last week.
<Highly dubious indeed>
I have examined all the other areas of Zoanthids in the tank and as yet haven't seen any others, so hopefully I lucked out and only got one. I guess we'll find out...
PS: Kudos for saying 'PLAH' back... most people are pretty dismissive of the idea because they don't try to figure out what it stands for. But I think it's the future of salutation. Now if we can just make it the future of Foreign Policy as well...
<I do agree. Cheers, BobF>

Re: Hitchhiking Aeolid (Better Pix) 9/24/11
Sorry, I neglected to attach the pictures to that last note...
<Mmm, I just cropped and optimized one of the prev.>
they probably still don't help much though... You guys are troopers. Thanks for your help.
<Nos vemos. 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>

Tritoniopsis elegans? 5/8/11
Is this the dreaded Soft Coral-Eating Nudibranch?
<Appears to be, yes>
Before I kill the thing, I'd like to make sure. it's about half an inch long. Very pretty, with blue tips on its edges.
It looks just like the Tritonidae, however it has blue tips. I haven't seen them with blue tips. Came in some coral.
Thanks, in advance, for your expertise.
<Welcome. Please see BillR's site here: http://www.seaslugforum.net/find/triteleg
Bob Fenner>

Nudibranch: Suborder Aeolidina, ID -- 3/10/11
<Hello Jonathon, Lynn here this evening.>
I found this little guy cruising the front glass in my reef tank this afternoon.
I was thinking it may be a Berghia but the colour seems wrong.
<Yep, it's similar but not quite right.>
I have it in a dish until I can determine what it is for sure. Any help would be appreciated.
<Unfortunately, I can't quite see enough detail to give you a positive ID, but I can tell you that it looks like a Nudibranch in the suborder Aeolidina (which includes Berghia spp.). Most of these Nudi's feed on Cnidarians (corals, anemones, etc.) so I would not put your individual back in the tank if you have any of these you wish to keep. If you'd like to pursue an ID, your best bet is to go through Bob's article/photos first, starting here (two pages): http://www.wetwebmedia.com/MolluscPIX/Gastropods/Opistobranchs%20Sea%20Slugs/Nudibranchs/nudibran5.htm
Next, I'd recommend going through the individual species sheets listed at the following link. Just scroll down toward the bottom of the page and you'll find suborder Aeolidina.
By the way, if you're able to get a close-up, detailed photo of your Nudi, do send it along and I'll gladly give you a hand.>
Thank you
<You're very welcome.>
<Take care, Lynn Z>

Nudibranch Question: Probable Tritoniid Nudibranchs -- 7/12/10
Hi Folks!
<Hi Adam, Lynn here today!>
Once again thanks for the invaluable resource.
<On behalf of Bob and the rest of the crew, you're very welcome.>
I have one question (with pics this time!) that I think I already know the answer to but I'm hoping you can confirm it for me before I commit mass murder.
<Fire away.>
In my 20 gallon Nano I had one large colony of soft leather type coral (I can't remember the type, they are tall, very soft and when their polyps are out they look sort of like an inside out lungs with bronchioles), go from massive, purple and healthy to melted in a matter of days.
It was during a pretty busy month for me so beyond making sure the water parameters were ok I didn't have much time to trouble shoot. However, a few days ago I noticed these white, feathery looking Nudibranchs in my tank.
How this many managed to appear without me noticing until now is beyond me,
<Unfortunately, it happens. They could have been introduced through attached egg masses, as minute juveniles, or as overlooked individuals that eventually reproduced. Some Nudibranchs blend in so well with their prey that hobbyists can have a difficult time seeing/recognizing them. They also tend to be nocturnal, so they can be easily overlooked until the hobbyist notices a decline in the coral's health, the individuals grow/mature, and/or the population explodes.>
..but I have another colony of the same type of soft coral on the other side of the tank that is neon pink and neon yellow
<It always makes me think 'dyed coral' when I hear/see the word 'neon' used to describe any soft coral, but if these are Nephtheids, then it's understandable. See Bob's article for more info/photos: http://www.wetwebmedia.com/nephtheids.htm >
-and was thus considerably more money - that I've noticed them gravitating towards. Upon closer inspection today I realized that there wasn't just one or two, but dozens of these Nudibranchs with what appears to be a dense mat of them right where the foot of the largest of the now vanished coral was attached.
<Double yikes!>
If I've done it right, clicking the links below should just open the pictures I uploaded to drop box in a browser window.
<It all works fine, thanks.>
I'm a terrible photographer
<Not so! Bad is when all you see is an indistinguishable blur!>
..so I tried to get them in as many different kinds of light as possible to highlight their anatomical details, as well as show one on the pink coral they've started moving towards.
<Thanks, the more information and photos people can supply, the better we're able to help.>
As you can see, the pink guy is no longer extending its polyps, though it does periodically molt and goes through cycles throughout the day where it expands and then shrinks. I suspect that these guys were the culprit behind the demise of my other coral, but I would love to know if you can identify them for sure as it will be the difference between them going in the toilet and going back to the store.
<From what I can see in the photos, you're most likely dealing with a Trinoniid of some sort (family Tritoniidae); that is, a soft coral predator that needs to go bye-bye. I'd use something like a turkey baster to remove all individuals, as well as any eggs (usually on/near the base of the coral), and keep an eye out for more. Please see the following link for a commonly seen tropical species, Tritoniopsis elegans. Note the variation in Nudibranch color and shape/placement of the egg masses: http://www.seaslugforum.net/showall/triteleg . We also have several FAQ's regarding Tritoniids, starting at the top of this page: http://www.wetwebmedia.com/NudiIDF7.htm >
Oh, and as I was writing this, I discovered one in the tank that isn't white, it's an orange pink. Possibly absorbing the colour of my pink coral as it eats it?
<Well, normally that would be my guess as well, but according to Bill Rudman of the SeaSlugForum, it sounds like prey color isn't really a factor; at least with the common species (Tritoniopsis elegans) linked above (see initial post, second paragraph).>
<You're very welcome and good luck!>
<Take care, Lynn Z>

Sea Slug ID: Likely Tritoniid Nudibranch - 5/23/10
Hi Bob, et al,
<Hello Nick, Lynn here tonight.>
Had a problem with one of my corals recently,
..lifted it up to take some photos and found these two slugs below
<Not good>
(Please excuse the Aiptasia, that's another headache).
<Yep, they definitely can be a headache!>
I believe they are the culprits for the nasty damage to the coral, coming out to eat it at night.
<If the damage was done to soft corals, you'd be right. What you have looks very much like a couple of Nudibranchs in the family Tritoniidae (Suborder: Dendronotina). Nudi's in this family prey on soft corals, hydroids, sea pens, and Gorgonians. I'd recommend removing any and all individuals (as well as any egg masses) with something like a turkey baster. Quarantining the corals would be a good idea, if possible. If not, keep checking the corals (especially at night) and remove every Nudi you see. Please see the following link for an example of a common tropical specie: http://www.seaslugforum.net/showall/triteleg >
Are you able to help with identification, and confirm they would be eating it?
<Well, it would help to know what kind of corals were being preyed upon, but since those look like Tritoniids, I'm guessing they're softies. For more photos of species in this family, please see the following link. Tritoniidae starts about 3/4 way down the page. Each species is a link to an information page with photos. http://www.seaslugforum.net/specieslist.cfm >
I've tried www.nudipixel.net but can't seem to find a match.
<There are an awful lot of Nudibranchs out there!>
Many thanks for your help.
<You're very welcome.>
<Take care.>
<Lynn Z>

Questionable Nudibranch... ID -- 3/25/10
<Aloha John, Lynn here today.>
Saw a Nudibranch off Hanauma Bay that I could not identify, despite going through 100's of Nudibranch photos. Can any of you identify it?
<I'd be happy to give it a try but I'd need at least one photo and any other information you could supply regarding size, color, location (on the rocks, coral, sand, etc.), along with anything else noteworthy that might not be visible in the photo. If you do have a photo (or several), please send them along and I'll do my best to get you an ID.>
<You're very welcome.>
<Take care, LynnZ>

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.

Worm ID: That's No Worm, That's Trouble with A Capital T: Tritoniid Nudibranch - 1/26/10
Hi Crew, Hi Mr. Fenner,
<Hello Claire, Lynn here this evening.>
I hope you all are feeling well.
<Thanks, just like the old song, I'm feelin' alright!>
I have a problem.
<I'm sorry to say that judging from the photos, you do indeed.>
A few days ago, during the night, I paid attention to a worm (looking like a slug) on the glass of the aquarium. I took a picture, but I did not send it, as I got only the ventral face.
Yesterday night, I remarked that two curious "critters" were on the rock of my Cladiella (closed for the night).
<Never a good sign, but helpful for ID purposes.>
I succeed to take an "acceptable" shot today and my questions are:
1)What kind of worm is it (I did not succeed to identify it myself from the WetWebMedia site)?
<Unfortunately, it's not a worm. It's a predatory Nudibranch, most likely Tritoniopsis elegans (family Tritoniidae). These little guys are very pretty but unfortunately eat soft corals like your little Cladiella. Have you noticed any damage to this, or any other softies?>
2) Is it a pest,
<When it comes to soft corals, yes indeed.>
..and if yes, how to eradicate it (I never saw it in the tank before,
<Hopefully they'll be out and about again tonight. If so, I'd opt for physical removal. You might want to try suctioning them out with a turkey baster. Be sure to have a net handy though, just in case one gets away. Please see the following link for more information (be sure to go through all associated links at the bottom of the page as well): http://www.seaslugforum.net/factsheet/triteleg
Google Tritoniopsis for the many WWM FAQ's re: http://www.wetwebmedia.com/Googlesearch.htm >
..but I suppose that there are a lot of creatures I never remarked too) ?
<Yep, there's a whole other crew that emerges when the lights go out!>
Thank you for your wonderful help and patience,
<You're very welcome and good hunting!>
Kind regards,
<Take care, LynnZ>

Re: Worm ID: That's No Worm, That's Trouble with A Capital T: Tritoniid Nudibranch -- 1/27/10
Hi LynnZ,
<Hi Claire>
Thank you for answering so fast.
<Well, I knew that if I were in your situation, I'd want to know right away!>
I have in my aquarium one very big Elegance Coral, one Goniopora, one anemone, a baby Bubble Coral, the Cladiella (the victim here) and two rocks with on each one a little colony of mushrooms (one colony of green mushrooms and one colony of green striped mushrooms), two false Percula (hosting the anemone) and two yellow Coris (yellow Wrasse).
<Sounds pretty.>
I did not notice any damage to any of the corals, but what I noticed is that the skimmer went amok today (perhaps because we had a power surge of 45 minutes yesterday). Everybody is looking fine, fully open and closing at night.
I hope that I will succeed to get rid of these beautiful pests tonight, when the actinic is the only light. I do not like the idea to trash living creatures in the toilets, but if I get the idea, I do not have any other choice.
<Unfortunately, that does seem to be the case here. This sort of situation always presents me with a moral dilemma. I have a very hard time destroying (or recommending the destruction of) anything that only through man's interference, has made its way into our systems. The way I see it, whatever the animal, it contributed to the balance of an ecosystem in the wild, so to destroy it because it has suddenly become inconvenient to our artificially skewed systems is just abhorrent. That's why most of the time I recommend that people try to find new homes for unwanted organisms instead of destroying them. One man's pest can be another man's treasure, so to speak. Unfortunately, in cases such as yours, the choices are limited. Those beautiful little Nudibranchs eat soft corals and that's it. If you left them in the display, they'd reproduce, go through the food supply, and all would starve to death. Removing them to their own tank, without corals, would end the same. The only real option for keeping them alive (since they cannot be returned to the wild) would be to keep them supplied with all the corals they could eat, which could become very costly. Without that option, the best and kindest thing to do is to put them down as humanely as possible. Please see the following link for more information re: http://www.wetwebmedia.com/euthanasia.htm >
And Thank you for the links - I am reading them now.
<Super. There's a lot of good information in there.>
Take care,
<And you as well>

Re: Worm ID: That's No Worm, That's Trouble with A Capital T: Tritoniid Nudibranch -- 1/28/10
Hi LynnZ,
<Hello Claire>
The Nudibranch who was on the photo was eliminated yesterday, I'm afraid to say that I did it the right moment I saw him on the Cladiella (before receiving your mail) with less humanity that it is described in the link concerning euthanasia. I took him off with tweezers and it was very hard because he was literally glued to the rock of the Cladiella.
<I bet!>
But I write you about your ethical considerations which I entirely share. It's the reason why I try to construct a little Indo-Pacific biotope including species non predators to each others. But of course, when you introduce a piece of live rock in your tank coming from the sea, you never know which inhabitants laid eggs there before.
<Exactly, or what's hiding out within the rock. You just never quite know what little surprises you're going to get. Most of the time, the organisms are good/beneficial; other times, not so much. At that point, you just have to weigh the risks and make the call to leave in place or remove.>
I'm happy when I see one of my two blue-legged Marshall hermits wandering naked after molting to find another shell without predators willing to eat him.
<Wow that is a predator-free zone!>
And I think a lot of people should have your wonderful sense of ethics concerning the living creatures.
<Thankfully, there seems to be many, many hobbyists out there like you that do share those ethics. Truly, it gives me hope for the future of us all.>
Take care, and thanks again,
<It was my pleasure, Claire, and thank you.>

Nudi/Worm ID? 10/6/08 Hello Everyone at WWM! <Art> Yet again I find that I need some advice, or, at least an ID of some sort... A few days ago I found this creature crawling around my 55 Gallon Reef Tank. I looked up the worm FAQ and had no luck. Whatever this thing is, it seems to be sensitive to light. If I have the lights off and shine a light on it, it quickly retracts into wherever it is anchored to. Another thing is, I've never seen it in it's entirety. So it could be a few inches long, or ...? The top of it has several "openings" <"Polyplacophora"> I guess you could call them, but I haven't been able to keep it in the open long enough to see if they actually open. It's kinda freaking me out. I was thinking a Nudibranch of some sort, but it looks like nothing in your 6 or so Nudibranch ID pages. Please help! I appreciate any info you can give me! -Art Perez <Is a Chiton... not harmful. Please read here: http://wetwebmedia.com/chitonidf.htm Bob Fenner>

Unidentified Nudibranch: Phyllodesmium briareum -- 9/6/08 Hello folks! <Hi there, Allison!> I'm having difficulty identifying this creature which came in on a chunk of green star polyps. At first, I actually thought it was a Condy that moved a lot trying to settle down! <It does look similar doesn't it!> Picture quality is the best I can get with my camera...I hope it is sufficient for identification. <It's great, thanks.> I THINK from as much as I can find on the 'net that it is a Nudibranch, possibly a Flabellina -type species. <Good work, you're in the right neighborhood (suborder (Aeolidina). What you have is a Nudibranch in the family Aeolidiidae, most likely Phyllodesmium briareum.> Nothing looks exactly like it (isn't that always the case?) <Yep, it's frustrating, isn't it!> ..but I hope if I can get a fairly confident ID, I can then research and find out if it can stay in my tank, and if so how to take care of it! <I'd remove it. These are obligate soft coral predators -- known to eat Green Star Polyps (Pachyclavularia violacea).> Behaviors I've observed so far: the tentacles(?) <cerata> along the length of the animal are light greenish-purple, with fluorescence at the tips. <Yep, all the better to blend in with what it's eating!> When gently prodded, all tentacles quickly wrap around the object--but it will not "hold on" to flakes of shrimp offered in this fashion <Understandable. The cerata are used for defense rather than for grasping food. Nudibranchs in the genus Phyllodesmium have a particularly neat adaptation for defense. Instead of being armed with potent stinging cells in the tips of their cerata (like most Aeolids), they instead release a sticky substance from the tips and, if push comes to shove, can detach the wriggling cerata - much like a lizard dropping part of its tail. The predator is left with an easy target, thereby giving the little Nudibranch a chance to get away.> (seriously--at first I thought it was an anemone!). <I can understand that. It's a pretty bizarre looking little creature!> It reacts to light, with tentacles gently stretching towards the light source, but is not a strong reaction, and doesn't position itself in relation to the available light. <Great observations! These Nudibranchs are 'solar-powered', that is they use light to sustain the symbiotic zooxanthellae within their bodies that help sustain the Nudibranch (like many corals)> Its body is long and narrow, with no discernible demarcation of head. It does have two lower "feelers" tipped with green (visible on one of the photos) and two more "horns" on top of the head. It moves about, but stays close or on the green star polyps. <That's typical. You, my friend, have made a terrific study of this neat little animal. Thank you so much for sharing it with us! For more information on Phyllodesmium briareum, please see this link: http://www.seaslugforum.net/showall.cfm?base=phylbria > I have not seen any damage to the polyps from this presence. <Not yet, but you will if it's allowed to remain.> Probably not important for this, but my tank is a 29g with CSL power compacts, live rock, and mushrooms and star polyps. Some snails, and a brittle star ("Bruce"),,,and one fan worm. Thank you so much! --Allison <You're very welcome and again, thanks for writing us! Take care --Lynn>

Re: Unidentified Nudibranch: Phyllodesmium briareum -- 9/7/08 Lynn, thank you so much! <It was my pleasure, Allison!> I poured over the sea slug forum for hours and hours <LOL Been there, done that.> (also Nudi Pixel...nice site!) <Yes, indeed. That site (http://www.nudipixel.net/) shows a lot of promise.> ..and here you give me the exact link! <Thanks to your excellent observations and photos, it was a piece of cake!> Thanks again! Allison <You're very welcome. Take care -- Lynn>
What is this? Goniopora Eating Nudibranch - Phestilla sp. 6/18/08 Hi folks, <Hi Tineke!> Can you tell me what this is? <I believe so. An important clue comes from what the creature is eating - Goniopora. It looks like it's well on the way to finishing off that poor coral. By the way, nice photo!> This was found at a night dive in the Red sea. <Boy, that's been a hot spot lately! Bob and some of the crew were there several weeks ago.> What puzzles me are the two *horns* (rhinophores?) <Yep, you have a good eye. The two slightly longer and lighter appendages on the right are indeed rhinophores.> ..Is this a anemone or maybe a Nudibranch? <It's an Aeolid Nudibranch in the genus Phestilla. I'm not sure what species it is, but you can see a similar individual here: http://www.seaslugforum.net/display.cfm?id=1813 http://rfbolland.com/okislugs/phes_sp1.html (larger photo)> Thank you for your answer. <It was a pleasure, Tineke.> Greetings from Holland, <Best wishes to you too from the US> Tineke Smit <-Lynn>

Re: What Is This? Goniopora Eating Nudibranch - Phestilla sp. 6/19/08 Wouw!!! <Good morning Tineke!> This is good news! I'm very proud of my picture! :) <You should be! It's a very nice photo.> Thank you for your quick answer. <Glad to be of assistance. Luckily, the photo showing the Nudibranch actively feeding on the Goniopora made all the difference.> Maybe I will send Rudman a copy of this Nudibranch. <Please do. I know he'd appreciate the photo, along with location information, etc., to add to his already wonderful site (http://www.seaslugforum.net/).> In the book of Nudibranchs of the world (Debelius/Kuiter) <Excellent book.> ..it also said that this one was seen in the Red Sea by Sudan. This one was a little bit more to the north in Lahami. When you don't know the name it is hard to search! <Very true!> Thanks to you I have the name and I can look under that name on the internet! <Makes all the difference, doesn't it!> You make me very happy! <I'm so glad to have been able to help. By the way, thank you for sending in your photo and inquiry!> Keep up the good work! <Heeee! Thankfully, this sort of 'work' is fun!> Greetings from Holland, Tineke Ede. <Take care and best wishes, -Lynn><<Ahh! Well done! RMF>>

Do you see the Nudi? Pointing up. Neat find and pic! RMF.

Shell or Nudi 07/07/08 Hey Sara, <Hello Tineke> Here the answer of Bill about the *hairy* Shell. He is also not able to determinate this complex thing. <Oh, how kind of him to answer you so quickly. He is a fabulous man. Thank you so much for sharing his email with us. And I think he is giving you an answer (but is simply being prudent in noting that he can't be certain with only pictures-- which is often very true of these types of animals).> Do you know already something about that strange sight I send you of the Goniopora columna? and <Strange site? I'm sorry, I'm not sure what you're asking. If you're referring the coral's general state of poor health, the culprit is likely the Goniopora eating Nudibranch Lynn IDed for you. The coral certainly looks as if it's being preyed upon. Or was there something else "strange" you're asking about?> Greetings Tineke <Best, Sara M.>

_____ From: Bill Rudman Re: Shell or Nudi Dear Tineke I am sure there is a snail shell beneath the brown 'growth'. I first thought your photo showed a snail with algal growth on its shell but the other photo shows an identical arrangement. Are the photos of the same animal? If not I cant imagine two animals with the same pattern of algal growth. Which made me wonder if the growth is in fact a elaborate periostracum produced by the snail. Some snails have a 'horny' layer on the outside of their shell and in some this has long hairs. In the family Ranellidae some species are called 'hairy tritons' because of this growth. There are some photos on the web - search 'hairy triton' - but in most photos of shells this layer is removed so the shell is more 'beautiful' for collectors. I suspect it is a snail, perhaps a ranellid, but I am afraid photos alone are not always enough to make an accurate identification. Perhaps it is algal growth. Sorry I cant help anymore Cheers bill =========================================== Dr Bill Rudman The Australian Museum 6 College St, Sydney, NSW 2010 Australia Visit the Sea Slug Forum at www.seaslugforum.net _____ Subject: Shell or Nudi Dear Bill, Again a puzzle. WetWebMedia couldn't find it and referred me to you, so maybe you can solve this problem. There exist also a picture of this one taken by somebody else on this site <http://www.aqualifeimages.com/> http://www.aqualifeimages.com click on latest release and then the thirds row from the bottom. This person don't know either what kind of Nudi this is. if it is a Nudi. I know the shell (Hydatina physis )looks very much but his mantle is not the same as on my picture. I hope you have the answer, Greetings from Holland,

Nudi? Possible Sea Slug -- 5/3/08 Hi guys <Hi Ian, Lynn here this morning.> I think I saw a Nudibranch but not sure. It was highlighted on the front glass panel otherwise would never have noticed. It was a tiny yellowish worm looking slug which was about 10mm in length and 2mm wide. It was moving like a Nudi and had two little feelers on its head. <It does sound like a sea slug of some sort.> Please help me to ID this and if a Nudibranch could it be a pest? <Sorry, Ian, but without a good photo I can't even begin to narrow down the search. As far as it being a possible pest, it's undoubtedly a pest to something, but what I have no clue. A lot of these guys are obligate feeders, feeding on one specific food item and that's it. Once that food source disappears, so do they. Have you noticed any damage to your resident corals/cnidarians (if you have any)? If not, chances are good that this little slug isn't too much cause for concern. You may see it out an about for a bit and then no more.> I have not recently introduced anything into the tank but at this size it could have been around for a long time without being noticed. <Many are nocturnal but can be seen in systems during the day when they're running out of food. Also, some are cryptically colored/adorned so that they blend in unbelievably well with their surroundings - which in quite a few cases is what they eat!> Your help is appreciated. <You're very welcome, Ian. For more information and help in narrowing down the possibilities, please see the following links (as well as the highlighted links at the tops of the WWM pages): Sea Slugs: http://www.wetwebmedia.com/seaslugsopisthobranchs.htm Nudibranchs: http://www.wetwebmedia.com/nudibran.htm Sea Slug Forum: http://www.seaslugforum.net/ > Cheers Ian <Good luck! Take care, -Lynn>

Re: Nudi? Possible Sea Slug -- 5/3/08 Hi Lynn <Hi Ian> Thanks for your prompt response. Will check out the web pages you sent. <Sounds good. What you want to do is look for shared traits in the species of sea slugs/Nudibranchs shown at the WWM links I provided. That should help you narrow the search to family level. After that, go to the Sea Slug Forum and compare each individual species listed under that family. It can be tedious and time consuming, but ultimately rewarding! Here's a quick link to the SSF species list: http://www.seaslugforum.net/specieslist.cfm > Cheers for now Ian <Take care and let me know if you're able to ID that little fellow! --Lynn)>

Nudibranch ID (follow up) 4/3/08 Hi Crew, <Hi Steve, Mich here.> After another night of searching your site (and links to www.seaslugforum.net) I think I have identified a hitchhiker that came on a soft coral I purchased today. I believe that I have the same unwelcome guest that another reader named Arthur submitted. <A link is always helpful...> As your article requested from him I have captured and photo'd this critter and thought I would forward the pics for your use. I am happy for these to be reproduced at your will. <Thank you for sharing.> I think it is a member of the Order: NUDIBRANCHIA Suborder: DENDRONOTINA Family: Tritoniidae but welcome your opinion. <Mmm, I'm not so sure, the description of the lateral lines appear different than you specimen. It's close but I'm not certain this is an accurate ID to the genus level. I would keep looking.> Following your answers to the other viewer I am pretty certain that this came attached to its' lunch ;) <Often the case.> so I have removed and isolated it (unfortunately the only thing I can think of is it to humanely kill it ?). <Mmm, I hate to recommend euthanasia. Though I don't have any great suggestions either. Most Nudibranchs are very difficult to keep in captivity because of their highly specialized diet and I'm not sure how much of your coral you're willing to sacrifice. I'm sorry, is a tough place to be. I'm sorry.> Regards
Steve Heath

I'm clueless - ID needed: Egg Ribbon -- 3/18/08 Hello! <Hi there, Sonny!> Hope you can help me to identify this creature. <Sure hope so!> I set up a nano reef tank about 7 month ago. I am into the hobby about 9 years now. All my water parameters (including Mg, Ca, Sr..etc..) are close to perfect. I keep my temperature at 78-80 degrees. 15-17 lbs of live rock, 20 lbs of aragonite, Marineland C-160 canister, Hydor Koralia Nano powerhead, AquaC Remora Nano skimmer with MJ 900. Current Satellite light system, 1 dual actinic and 1 dual daylight, 40 W each, 80 Watts all together, set up with a timer. Only 8 hours daylight. 1 small colt coral, 1 green eyed and 1 yellow polyps, trumpet coral. 1 six line wrasse, about a dozen hermits, about the same amounts of assorted snails. 1 sand shifter <Sifter?> star, 1 red thorny star, <Uh-oh, these two stars need much, much, more room in order to survive. They will not make it in a small tank.> ..and 1 cleaner shrimp. Very happy and healthy environment. Yesterday I noticed something on one of my live rock, something I never seen before. If you look at the picture the creature is right above my fish, and it looks like a target. <Nice photo!> Round shaped, and has circles inside.. The color is kinda clear whitish...Please help me identify this new critter for me! <Hmmm, it looks like an egg ribbon, possibly left by a Nudibranch or snail. No worries, these things pop up from time to time and usually disappear within a few days - as food for the system's inhabitants! Please see these links for examples of Nudibranch egg ribbons: http://www.seaslugforum.net/display.cfm?id=1128 http://www.wetwebmedia.com/nudireprofaqs.htm> Your help is truly appreciated, Sonny <You're very welcome! Take care, -Lynn>

Re: I'm clueless - ID needed: Egg Ribbon -- 3/18/08 Thank you very much Lynn! <You're very welcome, Sonny!> I forgot to mention this is a 10G tank. <Yep, I had a feeling it was when you mentioned the light fixture, but didn't want to assume.> I also forgot that I just introduced a lettuce Nudibranch (beautiful creature, I never had one before) about a week ago, so I suppose he's the source of those eggs. <You got it!> The sand sifter looks very happy, I don't see him too much though. <Unfortunately, these need a large area of mature DSB to survive.> The red thorny star is not the African red knob sea star, but I'm sure you knew that. <Well, I wasn't sure if it was Protoreaster lincki or Echinaster echinophorus, but unfortunately, neither is suitable for this size tank.> When I purchased him (I bought him and the Nudibranch at the same time) they told me they won't grow bigger than 3-4 inches. <Yes, although I've read differing reports on their size (ranging from 4-8'). Most say it's around 4', so I'd be more inclined to go with that number.> Should I take him back? <Yes, actually I'd take both of those stars back. They'll starve to death in such a small system.> He seems healthy. My only concern is that ever since I introduced him to my tank, he's not moving a lot. Looks like he settled down on one of my live rock, and he's been there ever since. I see him moving his tentacles and arms, but he just "sits" there. I don't know.. He's beautiful bright red and orange color.. Any thoughts? <Yep, if he's been in the same place for a week, that's not good. Even if he was doing well though, I would still recommend taking him back.> My heavenly Nudibranch is all over the place, grazing for algaes all day. Actually I don't have too much of nuisance algaes of any kind anymore, is there any supplement I can use if unfortunately ( I can believe I said that:-) I run out of algaes? <Hmmm, you could try Nori, but I'm not too confident that it will be eaten. These sea slugs are nothing if not picky little eaters! They tend to like one particular algae and that's it. Some like Bryopsis, others eat Caulerpa, etc. Sadly, they're usually short-lived in aquariums.> Again, thank you very much for the info and those great articles, I think you made my night much better. <You're very welcome. I'm sorry to be the bearer of bad news about the stars, but they really do need to be in a much larger system.> If you have chance Lynn, please let Anthony know that He rule the saltwater world.. By any means, He is the greatest. <Hey, what about Bob! I say he's the greatest! :-) Sorry, but I can't help being partial. LOL I just couldn't let that go without saying something! I've never met Anthony Calfo but he does seem like a terrific guy -- knowledgeable, funny and kind. I'm hoping to meet him at IMAC in May. At that time, I would be most happy to relay your message!> Thank you Lynn, good night <You're most welcome, Sonny. Goodnight to you too, -Lynn>

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>

Two Crabs and a White Nudibranch? 2/24/08 Hello crew! <Hi there!> I've attached a few pics of life (and former life) that I cannot identify. Whilst my intent was not malicious, the two crabs did not survive the extraction. <Unfortunate, but understandable - can be difficult to remove!> As you can see, one is missing several appendages. <Yep> I would've left them alone if my scarlet hermits were not being ripped to pieces at night <Yikes!> and if I hadn't read Calfo's opinion that crabs should be removed. <They can indeed be very destructive.> So, right or wrong, they are out and no longer alive. For the sake of learning and not repeating a mistake if they were harmless, can these be identified from the pictures I've provided? <They appear to be in the superfamily Xanthoidea. The hairy crab looks like it might be in the family Pilumnidae while the other could be in one of several different families. No matter, this group of crabs can be very destructive and I would have recommended their removal. Please see these links (and those within at WWM) for more information and photos for comparison: http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/swcrabs.htm http://www.nhm.org/guana/bvi-invt/bvi-surv/crab-g06.htm> Also, there is a small interesting white (Nudibranch?) life form in my tank. Pictures also attached. Ideas about ID? <Unfortunately there are just too many possibilities. I can tell you, however, that due to their specialized diets, these little guys do not usually survive long term in most systems. Please see the following links, especially the section at the bottom of the first regarding issues associated with Nudibranchs: http://www.wetwebmedia.com/nudispt3.htm http://www.seaslugforum.net/ > Thanks so much. <You're very welcome! Take care, -Lynn>

Nudibranch... ID, Behavior 2/23/08 Hi, <Hello Tina, Mich here.> I found a critter in my tank. At first I thought a piece of my pulsating xenia had broke off and stuck on the tank glass. Later I noticed it had moved. <Just as an FYI, Xenia can move... just very, very slowly.> Immediately I captured it and placed in a glass tumbler. It was sliding about the tumbler like a slug so as you do I went on your web site to ID my critter. <Excellent.> I have come to the conclusion it is a Nudibranch (Bornella calcarata) was the picture that matched mine the most as listed on page 2 Nudibranch). <Nudibranchs be a challenge to ID, even for some of the most experienced... Please see here heehee! http://www.seaslugforum.net/display.cfm?id=8163 > But before get rid of this coral-eating critter <Often are but not always, but their diets are usually very specific, and typically difficult if not impossible to provide in captivity.> I would like clarification of what it is as all of a sudden it stopped sliding around the tumbler, it's body turned flat and double its normal width and started to swim i.e. it's body kept bending in half and straighten again sort of flapping kind of like a caterpillar movement and it was swimming quite fast. <Nudibranchs can swim. Here is some video of a Spanish Dancer (Hexabranchus sanguineus) http://www.oceanfootage.com/stockfootage/Spanish_Dancer/owner%3Dkandykendall > I read on Nudibranch behaviour but this wasn't mentioned. I don't want to get rid of it if it is going to do no harm. <Really depends on what it is, a picture could help with identification, but I'm sad to say it will likely face an untimely death in captivity due to lack of nutritional resources.> Look forward for your reply Tina .x
<Cheers, Mich>

LR Hitchhiker: Sea Slug or Flatworm - 2/12/08 Hey WWM, (great site!) <Hey Bill, thanks!> Today, my roommate and I were upgrading from our 28g reef tank to a nice 46g bowfront. <Nice!> As I was moving the live rock from the 28g, I noticed a very small critter crawling on the glass. <How small/what size?> It looks like a slug of sorts, two antennas, slug like body, with very small bright neon green things running down it's back. <What kind of 'things' - stripes, bumps, ruffled/finger-like projections (cerata), etc?> I was amazed to find yet ANOTHER critter to appear, and in turn, it brought me directly to my computer in search of an answer. Any help would be much appreciated. <Hmmmm, it does sound like a sea slug or flatworm of some sort but without a photo, that's about as close as I can get to an ID. Most of these guys are obligate feeders that hitchhike into our tanks, survive until the food source is gone, then die out. Unless you have a tremendous number of these, or are seeing some damage, I'd leave them and enjoy them for as long as they're around. Please see WWM for more information, comparison: http://www.wetwebmedia.com/seaslugsopisthobranchs.htm http://www.wetwebmedia.com/nudibran.htm > Thanks Bill <You're very welcome! Take care, -Lynn>

Re: LR Hitchhiker: Sea Slug or Flatworm - 2/12/08 <Hi Bill!> Thanks, for that great info, <You're very welcome.> it appears to be very similar to Flabellina exoptata, which I found through your link. <Great.> I would say, it was about a centimeter long with finger like projections running down it's back, just like you asked. However, the colors weren't like anything I saw in those pictures. Maybe it varies coloring as it ages. <Color can vary quite a bit with sea slugs. I'm not sure whether it varies with age, but it's possible. I know they vary according to region, diet, whether they've just fed, or are starving, etc. It's entirely possible, though, that your little sea slugs could be another species within the genus Flabellina, or in the same family, Flabellinidae. There's a lot of red, orange, and violet in that family, but not much green, however. I did find one (Tularia bractea) that had green cerata. Here's the link for you to compare: http://www.seaslugforum.net/factsheet.cfm?base=tulabrac Also, here's the species page for the Sea Slug Forum. This is a terrific site. If you have the time (and T. bractea isn't the right species), you can look through, and compare the others listed: http://www.seaslugforum.net/specieslist.cfm .> Thanks again, and I'm sure you guys appreciate proper spelling and punctuation. ;) <Heheeee! Yes, we do, and thank you! Take care, -Lynn>

Sea Slug ID 2/11/08 <Hi Victor> Greetings to all. In reference to the E-Mail below, I managed to photograph the slugs so that you can confirm your ID or make a correction on your analysis. I isolated the slugs in another tank with a coral shrimp and the latter acts like they don't exist which to me seems unusual since these shrimps will attack practically anything they could get there claws on. I also removed the eggs from my tank and I placed one string of eggs with the shrimp, immediately he went for the eggs but as soon as he touched them he jumped back as if he was hit by an electrical shock. I can only assume that the eggs have some kind of protective toxin to ensure their development. Another observation is prior to removing the slugs one of them was attached to an anemone and as a result the same is in very poor condition, my conclusion is that it was being eaten by the slug and in the process toxin was deposited on the anemone resulting the condition mentioned previously. Also I noticed that when I touched the slugs the strands on their back would instantly spring up like a porcupine. Well I hope these photos will assist you further in identifying this species. Hoping to hear from you soon and once again thanking you in advance and also I would like to mention that your dedication to your profession is truly admirable and deeply appreciated by many around the world. <Your Sea Slug appears to be a Pteraeolidia ianthina, commonly found in the Lembeh Straits, North Sulawesi and Indonesia. This should help you do further research on the animal. James (Salty Dog)>

FAQs about Nudibranch Identification 4

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Related FAQs: Nudi ID 1, Nudi ID 2, Nudi ID 3, Nudibranch ID 5, Nudibranch ID 6, Nudibranch ID 7, & Nudibranchs 1, Nudibranchs 2, Berghia Nudibranchs, Nudibranch Behavior, Nudibranch Compatibility, Nudibranch Selection, Nudibranch Systems, Nudibranch Feeding, Nudibranch Disease, Nudibranch Reproduction, & Sea Slugs, Marine Snails 1, Marine Snails 2, Marine Snails 3,

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