Slug ID: Hydatina zonata - 6/26/10
<Hello, Lynn here today.>
This critter is being sold as a "Bubble Shell Sea Slug."
<Okay>
I'd like to know more about it before I purchase.
<Smart!>
A little research here and at the SeaSlugForum.net has me wondering if it's Hydatina physis or Bullina lineata. It doesn't look exactly like either, but there may be something I'm missing entirely. Any ideas?
<Yep, I think it's actually Hydatina zonata, a tropical Indo-West Pacific species which, according to Phil Rudman (of http://www.seaslugforum.net ), is likely one highly variable species with numerous synonyms (e.g. Hydatina albocincta).>
Mostly, I'm concerned about its diet.
<That's understandable and again, a smart move on your part because there is indeed cause for concern. Hydatina spp. are specialized Polychaete/worm feeders that prey on Cirratulids, aka 'hair worms'.>
Would putting this slug in an aquarium condemn it to a slow death because of a selective diet?
<I believe so, yes. That is, unless you could find a continual source of Cirratulids or an acceptable substitute (please see this link: http://www.seaslugforum.net/message/1690 ). For more information regarding these beautiful little snails, please see the following links:
http://shells.tricity.wsu.edu/ArcherdShellCollection/Gastropoda/Hydatinidae.html
http://www.seaslugforum.net/showall/hydazona
http://www.gastropods.com/3/Shell_983.shtml >
Attached 4 photos.
<Nice, thank you! Hopefully the above information/links will help, but if you have any additional questions or concerns, please let me/us know. 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,
<Uh-oh>
..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.>
Regards
<Take care.>
Nick
<Lynn Z>

Re: Sea Slug ID: Likely Tritoniid Nudibranch, now Nephtheid - 5/24/10
Hi Lynn,
<Hi Nick!>
Thank you so much (I must also say WWM is brilliant)
<You're very welcome and thank you!>
It is indeed a soft coral, and the only coral I currently have - I can't remember its name now, could it be a Nephthea?
<Well, coral ID's aren't exactly my forte, but that does indeed look like something in the family Nephtheidae (order: Alcyonacea). Unfortunately, Tritoniids love to eat Alcyonaceans.>
There are some photos attached if that helps.
<It certainly does, thank you.>
I wasn't sure I was able to keep corals alive in my tank, now it looks like they might have just been eating them.
<Likely so>
I think you are right, it may have been the white vs. orange that made me miss the pictures.
<I can certainly understand. That particular species varies from white, to orange to a reddish orange but if you don't know that, you can easily dismiss it as a candidate. I've done the same thing myself a time or twenty!>
On closer inspection, it indeed looks like they have laid eggs all over the base of the coral,
<Yikes! I'd hoped that wasn't what I was seeing in one of the previous photos.>
I thought about using a freshwater dip, but I believe I read on your site that the freshwater dip could kill the coral,
<Yep, corals do not like freshwater dips.>
..so will probably go with gently scrubbing them off in a bucket of tank water.
<Sounds good. Definitely get rid of those eggs and keep an eye out for more Nudi's.>
Regards
<Take care>
Nick
<Lynn Z>

Help With A Slug ID? Likely Dendrodoris nigra or fumata - 3/12/10
Hi WWM crew!
<Hi Adam, Lynn here today!>
I'm hoping you can help me with an ID on something that has apparently hitchhiked its way in to my 90g reef tank.
<Surprise!>
I will attach the two best pictures I have of it in this e-mail. I have to apologize for the iPhone photo quality but wouldn't it be my luck that when something cool and unexpected appeared, my big camera was sitting on my desk at work.
<Murphy's Law strikes again!>
It was about 1.5 inches long, half an inch across and looked very much like a slug with a ruffled skirt of tissue all the way around its body. It has two antennae
<'Rhinopohores'>
..and what looks like..a wilted flower the part of its body that I assume is its anus or maybe gills.
<Gills>
The pictures make it look black, but under the halide lights of my aquarium, it was the deepest royal blue I have ever seen on an animal. It had two rows of tiny white dots down its back (I played around with the gamma, white balance and exposure on these pics in PS so you can see the dots) and white dots on the tips of its antennae. I was a little shocked to see something that large and delicate pop up unexpectedly in my tank which has been up and running now for 6 months and my initial reaction after "wow that's pretty" was concern, as I know that some sea slugs/Nudibranchs can be quite dangerous in a reef aquarium.
<Yep, Nudibranchs in particular can be a real problem sometimes.>
Last month something started eating the polyps on one of my largest Acropora colonies in the night
<Uh-oh. Take a good look at the colony at night and watch for the usual suspects: Asterina stars, other Nudibranchs, crabs, coral-eating snails, a large Fireworm, flatworms, etc. Basically, look for anything on or near the coral.>
..and I thought I had identified the culprit to be a small, hair covered, mucous blowing crab that I removed,
<Heheee! That sounds like the person that sat behind me in Avatar a couple of weeks ago! Seriously though, the crab could well have been the culprit. Just keep an eye out for further signs of predation, just in case.>
..but I didn't know I had something as odd as a sea slug in my tank at the time. From the looks of its mouth parts which I got a peek at when it pressed against the glass, it looks like an algae eater but I've also heard that some sea slugs can be quite toxic.
<Yes indeed. There's a Sea Hare/Aplysiid from around Australia that's been responsible for quite a few dog deaths. Apparently the dogs find them washed up on the beach, eat them, and sadly, it's game over.>
I've been pouring through the sea slug forum species list at http://www.seaslugforum.net/specieslist.cfm,
<Love this site>
..but I'm afraid in my totally naive state I don't even know what family or Superfamily I should be looking in. Some members of the Onchidorididae family appear to have the right body shape, but I don't know how diagnostic that is.
<It all helps, believe me. By the way, kudos to you for even beginning to look through that long list of species!>
Any suggestions on where I should be looking
<Yes, take a look at the Nudibranch species Dendrodoris nigra and Dendrodoris fumata (Suborder: Doridina, Family: Dendrodorididae). They're common, tropical Nudibranchs from the Indo-West Pacific that feed exclusively on sponges and are often mistaken for each other. Both have white-tipped rhinophores and are mostly black as adults although they can appear bluish under certain lighting. For more information on these two beauties, please see the following links, starting with the FAQ titled 'Flatworm Identification: Actually, A Nudibranch: Dendrodoris nigra or fumata -- 2/17/10' here: http://www.wetwebmedia.com/nudicompfaqs.htm
Dendrodoris nigra: http://www.seaslugforum.net/showall/dendnigr
Dendrodoris fumata: http://www.seaslugforum.net/showall/dendfuma >
..or if this is dangerous?
<It is to your resident sponges. Other than that, it doesn't pose much threat to the system as a whole. The good news is that it's a fairly small Nudi in a large volume of water so any potential toxins released upon death should have negligible impact.>
I would prefer to not remove it as it's quite beautiful,
<It is indeed.>
..but considering how long it took to find it (and believe me I spend more time than I should staring in to my tank)
<Me too!>
..I don't even know if I'll ever see it again.
<You might not. It happens that way sometimes.>
Thanks again for your invaluable assistance,
<You're most welcome.>
Adam LeClair
<Take care, Lynn Zurik>

Re: Very Confused... much more reading...    8/10/09
I've attached pictures of the Nudibranch which I believe is a Caribbean sea hare but I am not sure?
<... not a Nudibranch, but an Aplysiid, a sea hare; Aplysia dactylomela looks like to me>
One concern that I have is if he will ink if stressed, or attacked?
<Might>
Although I don't think I have anything that will attack him. He has been in there since 7/22 and seems to be doing good so far, key words there! Thanks for the links about alkalinity and calcium. I will check them out now.
I hope you or another crew member can positively identify my Nudibranch so I know I am caring for him properly. Thank you very much
Bobi
<Do search, read on WWM re... Bob Fenner>