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FAQs about Nudibranch Identification 1

Related Articles: Nudibranchs, Sea Slugs

Related FAQs: Nudi ID 2, Nudi ID 3, Nudi ID 4, & Nudibranchs 1, Nudibranchs 2, Berghia Nudibranchs, Nudibranch Behavior, Nudibranch Compatibility, Nudibranch Selection, Nudibranch Systems, Nudibranch Feeding, Nudibranch Disease, Nudibranch Reproduction, & Sea Slugs, Marine Snails 1Marine Snails 2Marine Snails 3

To Bob Fenner please (micro-organism ID)   8/27/06 Hi Mr. Fenner, <Dom> Hope you're well. I recently got a new Montipora capricornis and it seems to do doing very fine overall. I already see some growth and the already nice colors are improving. But, in a specific area it started to bleach slowly. It's still progressing and I saw some 1-2mm pure white threads on the bleached areas. I cant see them moving. I took a sample and made a picture under microscope (please see attached file, magnification 40X). It doesn't move much under the microscope, only what I presume to be the head (top right corner on the picture) was doing a slow searching motion from side to side. Obviously its a worm and it looks a bit like a lamprey (the mouth for example) and it looks like it has a bunch of eggs attached on two points along the body. Can you ID it and can you give an advice on how to deal with it? Can it parasite a fish as well? <Highly unlikely> Many thanks! Dominique <Mmm, might be a trematode... maybe an "intermediate" form of a Polychaete species. Predaceous, not parasitic if so. There are quite a few possibilities: http://64.233.161.104/search?q=cache:9XOLiCgqBC4J:www.advancedaquarist.com/issues/apr2002/appendix. htm+worm+predators,+parasites+of+montipora&hl=en&gl=us&ct=clnk&cd=5 Based on its apparent morphology... The "basic" or S.O.P. for removal and prevention of such predators is best outlined here: http://www.liveaquaria.com/general/general.cfm?general_pagesid=351 Bob Fenner>
Re: To Bob Fenner please (micro-organism ID)   8/27/06 Hi Mr. Fenner, I did a Lugol's dip and discovered the real culprits: Nudibranchs (the worm I sampled probably has nothing to do with my problems after all, coincidental...(?)). They look exactly the same as those on the link you sent me. <Ah, yes... what you had thought were "eggs" were actually "naked gills"> I did a search on the net and found quite a few info but not very encouraging. In a forum Eric Borneman said there is no solution at all to that problem and that even Levamisole or Tetra Oomed doesn't really work. Some say they do work so I was willing to try anyway but they are both impossible to find. If you have a different opinion or hints please let me know. Thanks again ! Dominique <Physical removal and the search for a designated predator... Bob Fenner>

Aiptasia & Berghia verrucicornis... Nudibranch reclas. 7/19/06 Hi Bob, <Mark> FWIW I am sending a link to the Australian Museums' Sea Slug Forum <A most excellent site> discussing the fact the wee beastie sold as /Berghia verrucicornis/ (to remove /Aiptasia)/  has been described as a new species /Aeolidiella stephanieae /    http://www.seaslugforum.net/factsheet.cfm?base=aeolstep By whatever name, I just wish I could get hold of some of them here in Sydney... Regards & thanks for the wealth of info and enthusiasm your writings bring, Mark Phillips <Thank you for sending this along. Will post/share. Bob Fenner>

Nudibranch ID... sans pic?   6/17/06 Hi Crew,        Today I found a Nudibranch in my tank and was wondering if you could help me ID it and figure out whether or not it's harmful. It is about an inch long, white or very light cream in color, and has these sort of little fuzzy branches on it's back. We have several corals, a colony of xenia, a branching frogspawn, a large mat of green star polyps, and a colony of blue mushroom polyps. None of the corals seem to have been eaten, and all of the live rock we have has been in the tank since we started it six months ago. I believe the rock to be Caribbean in origin but I'm not quite sure. The tank is 330+ gallons in size so the toxic death doesn't worry me as much as the coral predation. I looked at your fact sheets, and it looked the most like Pteraeolidia ianthina, but less elongated. Please let me know if you have any idea as to what it is, what it feeds on, and whether I should remove it or not. Thank you for you time.                                                                -George G. <Need a photograph... there are many thousands of species... In the absence of any more information, I would siphon/remove this/these. Bob Fenner>

I Need Help Fast...Sea Slug Identification - 12/17/05 Hey, <<Hey>> I ordered some soft coral off the internet that came today.  I found in one of the bags what looks like a black slug. <<Indeed>> It's no bigger than an inch and on both it's eye stems (for lack of a better word) has one small white spot.  I don't want to let it into my aquarium if it will cause problems so currently it's floating in the aquarium in a plastic cup sealed with a rubber band and plastic wrap with holes poked in it.  The closest thing I can think of is the Keyhole Limpet Snail, but it has white on it's body and is rounder.  I can't get a very good picture either. Brian <<You're right...not a very good picture, but this doesn't look like a limpet to me.  I think "slug" is indeed a more accurate description.  Can't be sure, but the fact it came with your coral also indicates it is likely a predator of same and you are wise not to allow it in to your system.  Regards, EricR>>

Nudibranch Hello Guys and Gals: <Stan> About two weeks ago, me and the "boss" were at our LFS browsing around when she came across this Nudibranch. Well being it was her favorite color, cute and did nothing more then just eat algae, <...> it quickly became a "we have to get one of these".  Well needless to say, when I got the little guy home I put him in the QT.  A couple of days later, I decided to do a little research on exactly what it was that we had brought home.  Well needless to say, things didn't look very promising for the little guy.  I guess he doesn't eat algae, but instead has some type of specialized diet that dooms him in captivity. <Most species, yes> Well, its been two weeks now, and he's still active. <Starving...> I guess, any ideas as to what type of Nudibranch this is ?   <A Chromodorid of some sort... I'd try your pic, search on the "Seaslug forum"> Is he doomed ?  Is it true that when they die, they omit some type of poison that kills other fish in the tank ? <Possibly> Should I put him in my main tank ?  I'm really at a loss here. Not sure what to do with him. Thanks.
<... next time... study... before committing. Bob Fenner>

Nudibranch ID 6/14/04 My tank is about a month old, going through my various stages. Observed this guy truckin' on through one afternoon. About 1-2cm long, depending on how stretched out he was. I could make out the orange stripe with my eye, but I didn't realize the blue stripe until I got the pictures out of the camera. I'm guessing some kind of Nudibranch? <yes... correct> Thanks for any info you could share, & feel free to post the image on the site also if you like. Thanks again :) Pete Cushnie <the best you can hope for is that this is a head-shield slug looking for flatworms that you can grow/sustain it on. Worst case scenario is that it is a hitchhiker that came in and has no prayer of finding the very specific invertebrate prey (Cnidarian, sponge, etc) that it needs to survive. Either way it is of little consequence. We have extensive coverage of such Nudibranchs in our "Reef Invertebrates" book (Calfo and Fenner). And there is an outstanding website for the Opisthobranchs at the SeaSlugforum.com Anthony>

Nudibranch ID 4/28/04 Nudi of the Week is Dendronotus rufus Crew - We have a 120 Reef tank set up about one year. There is A LOT of coral in my tank. Pls advise if he can be harmful to our coral. Last evening after the lights went out about three hours later we saw two of these Nudibranchs on the glass. One approx 2 inches in length the other one inch. Never seen before. Are they a threat to our tank. Pls advise ASAP. Thank you as always. Regards, Cecilia <Cecelia... I'm not clear on the nature of the Behrens excerpt and pic you have sent (no explanation). Does your look similar to this creature? If so, then it seems, like with most any Nudibranch you find, that it is not safe or destined to live long in your aquarium. The best you can hope for is that its specific food does not exist in your tank. The worst is that it is toxic upon imminent death... or that there is viable prey I the tank. We know that such species are carnivorous by the presence of cerata/tassels on the back. IN the back of our "Reef Invertebrates" book (bibliog.) we list a website that lists the prey eating by a very long list of recognized Nudibranchs if you are interested (the bookmark slips me presently). My advice is to remove these slugs... and prevent other such pests or predators from entering your tank in the future by properly quarantining all new livestock without exception (rock, corals, sand, fish, algae... everything!). If you don't heed the need for QT, your next query to us maybe about a disease spreading through your tank :( Regards, Anthony>

Predatory Nudibranch...lack of QT 2/11/04 I noticed this creature in my nano tank about a month or so ago. It's white with pinkish highlights, and moves really slow. Is it some kind of worm, Nudibranch, or maybe a sea slug. I wasn't sure if it was a coral or not.  <it is a predatory Nudibranch... often cited as Tritoniopsis or Tritonia. They commonly come in with leather corals which is their prey. And they can reproduce in aquaria. A lack of quarantine use and letting this slug in can really make you pay/suffer. Sorry to see it my friend. You may have a hard lesson in front of you. These are coral eaters> I noticed that it moves around on one rock that has a soft finger type leather coral on it. Will it eat my soft coral?  <does a bear bring a Reader's Digest into the woods? Er... I mean. Yes, they ONLY eat coral> It never leaves the rock. <please do learn and apply proper quarantine habits for all new livestock (corals, fishes, rock, algae, snails... everything wet) to prevent such pests and predators from entering your tank and causing trouble. Anthony>

Mystery Slug Hi there. <Howdy> I've been searching your website but haven't been able to come to any solid conclusion about a mystery slug I found on my green star polyp.  The specimen looks like an adult, about 1.3 mm in length, with a variable brown and tan splotched back.  There are two dark spots at the front, which aren't eyespots but definitely some kind of antenna as they protrude from the main body.  There aren't any other extensions from the body; it tapers down to slime-trailing tail.  <Good description> Could you let me know if this critter is a good guy or a bad guy? <A "neither" guy in my estimation> I'm afraid he might have reproduced as I now have a couple of very small tan slugs with dark antenna hanging out on my green star polyp and the polyp itself is either not coming out due to irritation or is being devoured. Thanks! <This is some species of Aeolid Nudibranch: http://wetwebmedia.com/nudispt3.htm  And I would just leave it be. Bob Fenner>

Nudibranchs going to their deaths. Hi Bob, It's Mike (PF) again, While I was looking for other sources for live rock I came across https://www.gulf-view.com, aka Marine Life, Inc. I'm not sure if you're familiar with them or not, they are a Florida aquacultured rock outfit. <Yes, know of the company> While I applaud their efforts re aquaculturing live rock, they are selling H. edenticulas, aka Greek Goddess Nudibranchs as reef cleaners on their "special" page. I am writing them to inform them of the error of their ways and was wondering if you could add your voice in too, since your are a far more well known and respected member of the community than I am. <Will, gladly... by strange coincidence am doing some penance and spiffing up the "Nudibranch" page on WWM... have a couple of thousand (not a mis-print unfortunately) of mainly Nikonos extension tube shots of members... and could absolutely strangle (myself and) Helmut Debelius for his "reference" work on the group... either he's wrong on i.d.'s a great deal of the time, or the academic community are having a go with the public... Anyhow, please do addend your note to Marine Life with this small response, the link to the "Nudi" pc: http://WetWebMedia.Com/nudibran.htm and an offer on my part to lend them pix, info. if they'd like.> I hope I'm not imposing on you, but from all I've seen and read, and from talking to you online, I gathered you're against this sort of practice. <Never an imposition my friend. Your input is applauded. Bob Fenner> Thanks again, Mike

Nudibranch mis-purchase HI bob I purchased this strange looking creature today. It looks like a slug or snail without a shell. It is about inch & half long. The body is a purple with a pink tone. There is a solid white border around the top. On the top there are two tentacles which always remain extended. Then in the back there are approximately ten tentacles which extend and retract from time to time. It has placed itself on atop a piece of live rock. Could you please advise what it maybe and what coral it could hurt if any. Thanks for your time. Regards !!! <Yikes... very likely you're describing some sort of Nudibranch... please read over the scant coverage of these "naked gill snails" on the www.WetWebMedia.com site... if you just have this one small one in a sizeable system it will likely not cause much pollution if/when it perishes (most have quite restricted diets...). And your other livestock will very likely leave it alone. Bob Fenner>

Re: Nudibranch mis-purchase Dear Lorenzo- I understand that your mailbox may be full filling in for Bob in his absence. As they say curiosity killed the cat but they do have nine lives.  <I wonder how many catfishes have?> I am anxious to know the name of the creature I described in my message dated 6/6/01 below. Any information you can forward ASAP would be greatly appreciated. I want to also determine what it eats. Since I wrote you on 6/6 this creature has placed something resembling a very thin membrane but I don't know if it is waste or maybe eggs. It is extremely thin and is stuck on a plastic tube which is in the tank. The size about is about 1/2 inch long. I have noticed that it must be very strong because it hangs of the live rock in mid air for awhile at a time. Only a small fraction of its body stays anchored on the rock. Pls see my below for my original message. <Ah, still that unidentified Nudibranch... sad to state, most of these exquisite animals die of a lack of nutrition in captivity. I re-direct you to the article and FAQs file on this group posted on our site: www.WetWebMedia.com and the Internet for much more... Bob Fenner> Thanks for your assistance and prompt attention. Regards Cecilia Dowd-Kozak

Nudibranch? Sorry to bother you again bob, but while I was contemplating my Aiptasia problem, staring at my little slice of the marine world and getting lost in the tranquility and beauty of it all... I noticed a little white critter... he was minute, perhaps a 1/4" max? pure white... I noticed some appendages on the front that looked reminiscent of the rhinophores on Nudibranchs? but none of the pictures on WWM look even remotely close. <Possibly a "naked gill gastropod" my friend... WWM is in deed a work in progress... but you and I together would never document even the known Aeolids (let alone Dorids) in our lifetimes (discounting Wednesday nights out to the pub, chasing skirts...)> it has approx. 3 or 4 small appendages along it's back... but total lack of coloration... some sort of juvenile? is this guy a reef menace?  <Possibly to the first, unlikely to the last> I first saw him creeping towards my green star polyps and since I read about some Nudibranchs feasting on soft corals I sucked him up with an eye dropper and deposited on the opposite side of the tank... temporary solution at best if he is a coral muncher... any info would be appreciated. <Enjoy this world my friend. Bob Fenner> thanks form me and my mini-reef Ben

Night Life... Mr. Fenner, I know you are inundated with queries, but... I read on your site about an individual who was shocked at the amount of life found in her tank with the lights off. I had tried this in the past, with little success. The tank was new and there was some ambient light coming from an adjacent room. <Ahh...> This morning, I went stalking my tank with a small pen-light. WOW! The night time activities far outweigh the day. <Not surprisingly, eh? Much less likelihood of being eaten by organisms in the dark of the night> I found things (rather large) that I am quite sure that I neither knowingly put in there, nor have seen in the past. I found a 1.5 inch "hairy" crab. Will identify him later today. I did try to research another occupant, but am up against the wall. It is an oval shaped, 1.5 inch solid purple (plum), flat organism. It appears to have a head end and the edges "undulate", however, this is not the means of locomotion. It slides along like a snail. On it's back is a closed, slit-like orifice similar to the mouth of an anemone. In fact, at first I thought it was an anemone, however, after prolonged exposure to the light, it beat feet into a hole. Any ideas? I looked through all of the photos I could find in your material. I am leaning toward a flatworm of some type, but perhaps a Nudibranch. If you have any suggestions, I will follow up appropriately. <These would be/are my general guesses as well... the Nudibranch group first, then perhaps a Platyhelminth...> Any dangers? I would not assume so as it must have been in there for some time. <Not much... if the tank is large, well-filtered/aerated/circulated enough... should be fine to leave all as is. Bob Fenner> Thanks again,
-ed

Nudibranch ID Hi guys, I was wondering if you could identify this slug as potentially harmful.   <it is, as evidenced by the Tassled cerata dorsally that are extensions of the digestive track in gross terms and contain the stinging cells of Cnidarian tissue that it has consumed (eats coral, anemones)> He rode in on what I believe to be a pipe organ coral (see attached).  I found him in the bag and figured he was herbivorous <Ahhh...no> but he STAYS on the pipe organ.   <Ahhh... ya> I've noticed on the polyps of the pipe organ some "branches are missing now but I've never actually seen the slug near the tips. <night time is the right time> I've actually had the slug living in a bucket of change water (water I removed from the tank) since he's under suspicion.  Any ideas?   <yep... put the creature in a jar of formalin and take it to club meetings to warn other aquarists. But seriously... a shame that this creature will not survive in captivity for you. It has a very specific diet that you cannot want or afford to meet. Please do take some better and clear pictures of this creature in a another vessel (dorsally in a bright white cup perhaps). And do share the photos... we'd love to have them! Highest resolution possible for our website and possible book/magazine print with your permission.> Thanks in advance. Arthur
<ciao, bud... Anthony>


Can you help me identify with this photo? I have others. Shot in thirty feet of water in the Bahamas. Bob Fenner By Bob Fenner
Dear Bob, This is indeed a species of Bornella. Fortunately, only one has been described from the Caribbean region so I can pretty confidently identify it as Bornella calcarata. Have a look at the other photos and messages on this page to see the variation in colour of this species. It seems the broad white band down the dorsal midline is present in some form. The fingerlike 'oral veil' on either side of the mouth is very characteristic of the genus. Best Bill Rudman

Your photo on the Forum (SeaSlug... it's fabulous) Hi Bob, I saw your photograph of Bornella calcarata on the forum this morning. Where did you take the photograph? <Nikon N90, 105 mm, Velvia (Fuji 50 ISO) film> How deep was it? <Appx. 45 ft> Was it a day or night dive? <Day> I spend a lot of time in the Bahamas and would love to photograph this Nudibranch. Thank you. Anne DuPont <Thank you for the note, Bob Fenner, WetWebMedia.com, http://www.WetWebMedia.com/nudibran.htm>
Re: Your photo on the Forum Thanks Bob, Where (what island) was it photographed? Thanks, Anne <Had to get out my originals. In Tuna Alley, twixt N. and S. Bimini... during a Oct. trip out on BlackBeard Cruises out of Miami... and more like thirty feet (according to note on slide) of depth. Bob Fenner>

Nudibranch Identification Question Three Nudibranch showed up in my tank via a piece of coral and I wondered if you might know their name/eating habits? They are bright orange all over (no other colors present). They are covered with tentacle-like polyps from tip to tip. None are longer than 3 inches. There is not really anything else particularly distinguishing about them, other than the above features. <I am going to guess Nudibranchia eatyourcorali :) Sorry, but I really have no idea. Do please see here http://www.wetwebmedia.com/nudibran.htm http://www.wetwebmedia.com/nudispt2.htm http://www.wetwebmedia.com/nudispt3.htm http://www.seaslugforum.net/ and follow on through the other linked files for additional pictures. My best guess is that these are possibly predatory for that particular coral. Nudibranchs in general of very specific in what they eat. It stands to reason they hitchhiked into your tank on the back of their food source.> Thanks in advance, George <You are welcome. -Steven Pro>

Re: Nudibranch Identification Question Steven, Thanks for your quick reply and information sources. Through your help (the links) I identified the little buggers! They are Family Tergipedidae, Phestilla melanobrachia. <They did not happen to hitchhike in with a Sun Coral/Orange Cup Coral/Tubastrea?> Thanks, I would not have identified them without your help. George <You are welcome. -Steven Pro>

Re: Nudibranch Identification Question They did hitchhike in with the Orange Sun Coral. I am starting up a new 7 gallon saltwater set-up and the fish store gave me some "bits" from their tanks to help me get started. One of the larger bits was an Orange Sun Coral that was ~75% dead, only two polyps were left. I was happy to have the free coral, so I did not complain. What surprised me is that when last night the two "polyps" got up and cruised around the live rock. <They were probably looking for more Tubastrea.> After a closer inspection, it looks like I have 3 Nudibranchs (1 large, 2 small) and good sized bunch of eggs on the coral that they came in on. I would really like to keep these guys alive, but I have to do the cost benefit analysis of buying Sun coral to keep them feed. this could get expensive. <Yes, but it would be interesting though. I know Tropicorium was propagating Tubastrea and if my memory is correct, a gentleman by the name of Yaiullo had them spawn in captivity. I know he wrote an article about it. I would search for Tubastrea and Yaiullo and determine if you can/desire to set up a second tank for raising food. -Steven Pro>
Re: Nudibranch Identification Question Thanks. That's a great idea. People are going to think that I am nuts, raising coral to feed Nudibranch! <Tell them you are on the cutting edge. -Steven Pro>
Re: Nudibranch Identification Question
I searched for Yaiullo, and he did publish an article on spawning Tubastrea in a 1994 edition of Aquarium Frontiers. The AF archive does not go back that far. <I think AF was still an actual paper magazine at that point. I looked around for an online version myself but no luck.> I tried to find an e-mail address for Joe Yaiullo, to no avail. Do you by chance know his e-mail, where he might be working, or organizations he might be associated with? <I know he is working in New York at a Public Aquarium. Perhaps someone that reads the dailies on www.WetWebMedia.com will read this and find/know of a link to his article. -Steven Pro>

Weird little critter.... Hey guys. I am just starting a low light 55 gallon reef (well, 3 months so far). The tank was Fish-Only before for perhaps 6 months. 15" in-tank counter current protein skimmer, 90 watts of N.O. lights, Coral-life and Ocean-life bulbs. Got maybe 20 lbs of cured Fiji rock so far, and some coral skeletons. Crushed coral substrate. Livestock; a few Sabella feather dusters, 6 Astrea, Mushroom, Button and Colt corals. Anyway, I bought a piece of rock with what I thought was some kind of anemone, bluish-black with a white stripe in the center. I placed the organism right under the light, and to my surprise, by the next morning it had crawled away. Haven't seen it for like 2 weeks until today when I was moving rocks around. Got a real good look at it too. It has a very dark blue center perhaps an inch long and a frilly translucent mantle, it would be a great display critter if it came out in daylight. The white stripe is some kind of bone or shell, which the mantle has enclosed from underneath. Two short feelers/tentacles/pseudopods extend from the front. It looks similar to a type of snail called an Opistobranch (please excuse the spelling) or something like that. <indeed... does sound like a shell less nail/Nudibranch> Is it going to be any danger to my other sessile inverts? <tough to say... more likely it will starve to death as most are so specific if their diet. There is some home that yours eats flatworms which are possible to culture in display aquariums. Do browse through some specific references on Nudis to get a species ID with hope that it is recognized in the hobby for its needs. There are many dedicated websites if you care to de a keyword search.> Well thanks for your time. Simon : ) <best regards, Anthony>

Is this a flat worm, snail slug, Nudibranch or what?? Dear crew, I found this snail type invert in the tank after buying live rock from the LFS. I've looked thru the website but haven't found anything looking like this. It is a rose pink color about an inch long, has two rows of branch like "tentacles" along its back, with a crown for its head. I'm leaning toward a Nudibranch what's your opinion? Thanks, Cindy <Looks like a Nudibranch to me. Might live, might not... likely not a problem either way. Bob Fenner>

Creature ID - 2/14/03 Mr. Fenner, <Anthony Calfo in your service> When my lights came on I found this orange and green slug-like creature with about 12 stringy tentacles.  It looks like a hydra but I assumed they were microscopic.  It crawled into the rock except for it's tentacles, which it left out, probing the rock.  I believe it exudes some sort of white powder as you can see on the rock in the pic I've included.  I looked through your articles and on the web and haven't really found much about this.  My main question is if this is good or bad to have wondering around.  I don't have a macro lens, so that is the best I can do for a visual. Thanks for your time Donovon Bodine <The effort to take the image is truly appreciated. Alas... it came through very blurry. Still... it has a reminiscent form on a Dentronotid sea slug. Without any more info (number of tentacles to that are "head-oriented/AKA cephalic, are there sparse tassels on the back, in pairs?, etc)... I'm wondering if you don't have something like: Bornella calcarata  Please use that name in our search engine for WWM to find a picture on the site to compare to in gross form. At least to tell us if it is even a true sea slug. If it is a Dentronotid species specifically... then it eats coral or like cnidarians (perhaps even jellyfish... yikes!). That would be bad. Kindly, Anthony>

Snail?  Nudibranch? >Hi, WWM Guys and Girl, I think that it is a Nudibranch.  Someone at the LFS suggested possibly a limpet, but I don't think so. Don't those all have shells? >>Girl Marina again.  ;)  To the best of my knowledge this is correct.   >I'm going to try to send the pics again in a zip file, perhaps they'll come through that way.   >>Do check the extension of the file type, this may have been the initial problem, though I'm hardly an expert.   >I'm inclined to think that it is not predatory by the lack of cerata on it's back, is this a "fairly" safe assumption??   >>This I cannot confirm or deny.   >I appreciate all the hard work you guys do saving our critters from our lack of experience. >>Heh, we try.  Do hope we've been of help to you and everyone else who reads this stuff.  Marina

Nudibranch id 6/11/03 hey guys, thanks as always.   <our pleasure> I noticed that my star polyps have been shut for almost 2 days straight. I inspected last night and found a couple Nudibranchs on the mat.  I have not seen them anywhere else in the tank.  however, I don't notice much damage being done to the mat itself.  I caught one with a turkey baster. sorry for the fuzzy photo, but its the best I could do.  is this predatory?  to the polyps retracted? <yes... clearly predatory as indicated by the presence of cerata on the back (the "tassels"). They are for storing, in part, the digested stinging cells of Cnidarian prey like your coral. Do seek and remove, my friend (the opisthobranchs... not the coral <G>). Best regards, Anthony>

Unknown Nudibranch (possibly, anyhow) Okay, I've looked and looked online, and I can't ID my new little friend I found in my reef (at least I hope he's a friend, or at least not an enemy). Two days ago, out of the blue, this little black slug with a red-ring-looking thing showed up. Must have been on the LR, but the tank is 10 weeks old, so he must have been hiding somewhere. Anyhoo, I was wondering if anyone knew what this is exactly. It appears to be some sort of Nudibranch. The attached picture is, so far, the best one I can get. It /does/ have that little ball thing on his back like most Nudis do. Any ideas? Thanks!!!  ~Eric aka Dakota on the forums. <Does look like a Nudibranch to me as well... Has rhinophores, body shape as such, not as a flatworm for instance. I would say it's not likely a problem as it "spontaneously arose" from your system... that is, it likely "has food", and won't toxify your system if it dies. Nice pic. Bob Fenner>

Nudibranch ID? 8/2/04 Here is a better pic of the little pests. Is there any other info you can give? Any help is appreciated, thanks <again... Ids from pictures are unreliable if even possible. I see that you used/borrowed a pic from John Susbilla.  I know this chap... he's a Bay Area club member (SeaBAY perhaps). Do e-mail John for an ID of this/his snails.  He's a great guy. Anthony>  

Nudibranch Identification I would greatly appreciate it if you could help me identify my Nudibranch, so I could find out what type of sponge he feeds on, or what type of food he needs.  I have had a very difficult time identifying it, and therefore am positive I am not providing the proper care for it like I would like to.  Any information you could give me I would sooooo greatly appreciate it.  Thank you.  The closest I got to identification is Durvilledoris lemniscata. Paul <Mmm, maybe... or a Chromodoris species. I would send this along to the folks at seaslugforum.net Bob Fenner>   sorry if the pic is a little difficult to decipher. 


Unidentified Nudibranch I'm hoping someone with more Nudibranch identification experience might have an idea about the two pink-white slugs that appeared in my tank recently.  I'm afraid my pictures are coming out slightly blurry.  I haven't added anything but fish to the tank in about 6 months. Suddenly, one of the soft corals started to look increasingly ill.  Then the slugs pictured appeared crawling all over it. <Likely a predator-prey relationship...>   They have stayed on the coral for 3 days and I can only assume they are eating it.  Odd curly white strands have also appeared in bunches in the immediate area. The slugs are less than 2 inches in length and the strands can be as long as 5 inches- I have seen the strands appearing to come from the slugs themselves like waste product (or reproductive structures?). <Likely the latter... This appears to be some species of Dentronotid, at least a dendronotine. I would send your pix, query to my fave site for such: http://www.seaslugforum.net/ and ask those fine folks what this is. You will have to decide whether to risk your soft coral's health/life or rather to eliminate these Nudibranchs. Thank you for sending this along. Bob Fenner> Any guidance would be greatly Thanks.
- David
Will do.  Many thanks for this, your excellent publications, and very helpful website!  I'll let you know if seaslugforum.net can identify these beauties.  - David <Real good David. If they can't do it... I don't know who might. This is where I send my Sea Slug pix for IDs. Bob Fenner>
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