FAQs about Nudibranch Identification 7
Related Articles: Nudibranchs, Sea Slugs,
Related FAQs: Nudi ID 1, Nudi ID 2,
Nudi ID 3, Nudibranch ID 4, Nudibranch ID 5, Nudibranch ID 6, & 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,
Unknown Nudibranch 9/10/17
Can you ID this?
<Mmm; appears to be a Tritoniopsis sp, may be T. elegans... soft coral eaters.
help id Nudibranch 7/23/17
Found a dark Nudibranch with white tips on frills and antenna, came as a
hitchhiker on red macro algae, less than 1/2 inch long when stretched out.
Would like to know what kind this might be and what it eats.
<My guess is on a Flabellina sp.; perhaps F. exoptata:
Most Flabellinids eat Hydroids>
So far a hermit crab tried to pinch it and the slug retracted, the hermit looks
like it got stung or slimed and backed off cleaning it's pincer arm. Slug moved
up a rock and then floated off - drifted in the water current a bit (fortunately
not getting sucked into the filter) and landed in back of the tank out of view.
Hermit is doing ok now. Attached photo. Any insight to this critter is
appreciated, thank you.
<Welcome. Bob Fenner>
Re: help id Nudibranch 7/24/17
<Ah, welcome. BobF>
Reef critter ID, input re comp.
Hi i need help with an id on this creature. I believe it's some sort of
Nudibranch just don't know the exact name and whether it is a reef safe or not.
<Is a Nudibranch... don't recognize the species right off; but would keep an eye
on... IF it's eating something/s that aren't of interest to you; I'd keep. Bob
<14 megs? We only ask a few things; one is that folks limit their file sizes...>
I have a 65 gallon reed tank that is flourishing. I have very little problems
and all of my corals and inverts are doing very well. The only fish in the tank
is a mandarin goby. It is also doing well.
<..."often cited as Tritoniopsis or Tritonia. They commonly come in with leather
corals which is their pre.....">
In the last week, my newest addition (had been in tank about 2 weeks with no
problems) a 4 inch blushing leather coral, started to fail.
<Bingo; and BINGO was his name oh!>
One of its lobes died off. So, I moved it to a higher light zone. Slowly but
surely it died off one lobe at a time. It has completely disappeared as of about
3 days ago. Today, I saw what appears to be a large Nudibranch. I took a
picture. In your opinion, do you think this is the culprit? It actually looks a
little bit like a blushing leather in coloration. I wonder
if it was smaller before eating and went unnoticed until the leather was gone.
Now it is cruising the tank looking for more. Anyway, I can't find a similar
picture anywhere to identify this Nudibranch. Have you seen one like this
before? Do you know what it is?
<Please read here:
<Welcome. Bob Fenner>
<Appears to be a SeaSlug (Opisthobranch) of some sort... need to see entire
organism. Bob Fenner>
Hi it was suggested to me to ask if you would identify this creature that has
suddenly appeared in my Marine tank. I have asked on a couple of groups I'm on
but no one seems to know what it is. The last suggestion was a sea hare, but
personally I don't think it is. I have attached a photo.
re: Identification please
Here are more pics
<Strange.... the sensory processes on the head don't look like rhinophores (of
nudi.s), but the girdling underneath the body does.... and the animal lacks
dorsal "gills". What are does your live rock hail from? What else with hard
structure have you added recently (the last few mo.s)? I've scanned my sea slug
ref.s, and the Net and don't see this Gastropod. Oh, and about how big is it?
Re: Identification please 2/1/17
The main rock wasn't live, we opted for bleached rock as we had lost everything
when our tank crashed. The only live rock I guess would be when we have bought
we have recently had a sun coral from our lps which had been fragged. This
hasn't done well in fact the guy from the shop said it looked like
something was eating it. Whether it's this visitor or not I don't know. As
regards size when fully stretched out I'd say he is about an inch and a half and
goes long and slim, but then he can change and get more flat and broad. He is at
the moment climbing around the glass at the front of the tank where he has been
most of the day.
<Is it possible that the gills were chewed off here? This looks more like a
Nudibranch than anything else. Am going to ask a few friends for their help. Bob
re: Identification please; and posted to Joe via FB
Thank you both Bob and Joe I will indeed remove from my tank.
<And you, BobF>
Nudibranch id please 1/28/17
Hello there, I first want to thank you for previous help a long while ago.
My issue was dozens of hermits large and small disappearing completely,
shell and all. You (can't remember which crew member in particular) had
suggested it sounded like I could have a predacious worm. Soon after I
managed to find 2 large fire worms when looking at night. I managed to
remove the pair, and haven't lost a crab/snail/shrimp since!
But as for my current question. Yesterday I purchased some corals,
specifically a colony of Ricordea yuma, a colony if Zoanthids and a colony
of Palys. In addition to the wonderful turbo snail and emerald crab
hitchhikers I scored, this morning to my surprise I have a tiny Nudibranch
and a small starfish on my glass. The starfish is I believe an Asterina
(grey with 6 arms) but it's at least twice as big as any I've seen in my
But my main concern for the moment is the Nudibranch. Of course I'm worried
he could be the type that eats Zoanthids, although I'm hoping that the fact
that I have found him in the glass is a good sign. Regardless, he is in jail
for the moment. I should add that I have now inspected my new Zoas and don't
see any eggs as of yet.
I would really like to keep this guy if I can, so please tell me if
you think he is a good Nudi or a bad Nudi.
<Mmm; appears to be a Aeolid... do consume Cnidarians... often look a lot
like their prey>
I hope these photos are clear enough to get a good identification. He is
about a quarter inch long.
I would also like to know, if he does end up being a Zoanthid eating
Nudibranch, is that what they eat exclusively?
<Don't know; but too likely so. See the Net w/ the family name...>
Rather than killing him I would like to set up a nano tank to keep him and
any other future questionable hitchhikers but if he will die without
Zoanthids I guess I have no choice.
Thanks in advance!
<Welcome. Bob Fenner>
Still cycling my 28 nano but saw my first official hitchhiker today...guessing
it is some sort of Nudibranch! :)
<Ah yes.... do you have Cnidarians present? Do see WWM re Nudibranch ID. Bob
By the way, no Zoanthids in my tank, still cycling. There looked like
there were some tiny remnants of a yellow sponge that matched his tentacle
coloring--wonder if that was his food?
<... possibly; though I doubt this. Likely some other stinging-celled life on
your live rock is supporting this/these for now.>
Don't want a pest, but if he just eats sponges or won't like explode into a
population of nudis then I'll let him wander in my tank.
<Likely what I would do as well at this juncture. BobF>
So last night I searched the tank with a light and saw something yellow,
matching my little Nudibranch friend. Seems you were absolutely right, seems to
be some kind of coral?
<This looks like a sponge to me... no polyps; but a few osculae in view>
I'm not even sure if it is still alive?
<Appears to be>
Sort of bummed my Nudibranch friend is a coral muncher!
<Mmm; night not be. Most consume hydrozoans....>
you'd like to see the puzzle come together, happy New Year! :)
<And you! BobF>
Aeolid Nudibranch ID? 9/14/15
A friend on a reef forum has suggested you may be able to identify these slugs I
have been finding in my aquarium. She suggests they might be either *Aeolidiopsis**
ransoni* or a *A. harrietae*.
<My money is on the latter. A fave ref. (Bill Rudman)
I'm attaching a
number of photographs of a number of different animals. All have been
found on or very close to Zoanthid soft corals within my reef aquarium.
<Do consume Palythoa>
The largest animal is around 10mm long with the small ones being 2-3mm I look
forward to hearing from you.
<Thank you for sending this along. Bob Fenner>
Re: Aeolid Nudibranch ID? 9/15/15
Many thanks for the identification. I'm busy removing them off my Zoanthids...
<Ah yes; I would>
<And you; BobF>
Aeolid Nudibranch ID?
I have been successful for years due to wealth of information this site has to
offer. Thank you for your time and service! Now I am hoping I can get a
verification of what I think I have learned after reading lots of links here.
I have had a pistol shrimp / Goby combo for the last three years. This year we
slowly started adding corals to their tank. I have diligently QT everything we
bought and everything has been cleared and in the display tank. Well, (yep here
it is...) except some rock rubble that I bought last week for the pistol shrimp
(he gets so excited about new rocks outside his
door) from my local saltwater retailer's live rock bin.
Two days later I saw this guy on the glass, he was about the size of a grain of
rice, and I removed him from the tank (picture attached taken with a magnifying
glass). Two days after that my only piece of Montipora has batches of these same
things around the base.
<Trouble; are Montipora eaters. Need to isolate, and likely dip/bath all
incoming corals to avoid such undesirable hitchhikers>
The Montipora is now in a hospital tank and manual siphoning of the Nudibranch
has begun. I believe from what I have read that these are Aeolid Nudibranch but
if you can verify I could not find many definitive pictures on the link for
I just want to make sure I have the right plan of attack by making sure I am
reading about the right thing. I have not seen a single one of these Nudibranch
on any other SPS or LPS I have (although I will continue to check daily).
<There are a few approaches... I'd be reading, and pronto. Bob Fenner>
What is this?
<Ahh; Tritoniopsis; a soft-coral feeding Nudibranch. Bob Fenner>
Orange and Yellow Nudibranch... Iatrogenic troubles...
Hi, I have a question regarding a Nudibranch I purchased last month. I
have included a picture of him. Beautiful specimen, very interesting to
watch. I bought him from my LFS, which is normally pretty solid.
The Nudi came in as an extra.
<A bane of the trade... go ahead>
I saw him and asked about him. I was told they were not given a
name, and as such could not sell it to me because they were not sure
what it ate.
<I do like their honesty here>
The next week I came in and was informed that they had indentified the
Nudi. I was furnished with a picture in a book, which identified the
Nudi and said it ate only live red sponge.
The picture looked exactly like the Nudi, so I went and bought a
<... there are many different types of reddish poriferans. Some are NO
and then came and got the Nudi. I do not recall what the Nudi was
called, but I can find out.
Well, the Nudi didn't ever touch the red sponge. Since I've
never had a Nudi(other than lettuce)
<And these aren't Nudibranchs... see WWM re Elysia>
I assumed he was eating and I was just not catching him. I came home
last night and the Nudi was not moving, just sitting in the corner...not
usual for the specimen from what I've witnessed. I also noticed my
livestock in the tank not acting normal, so I kept and eye on the tank.
This morning I woke up and the Nudi had not moved, so I picked
him up and smelled him.
Dead. So I flushed him and tested the water. Parameters are as
Mg-I don't have a test
I know my trates a high, but this is a biocube with many
and some sun corals. Only 3 fish, a potters angel
and a pair of gold striped maroon clowns.
<These two too>
I struggle to keep the trates around 40, so 80 is high even for what I'm
used to seeing. All my anenomes were sucked up and not behaving
<Opisthobranchs can definitely be trouble when
they die, dissolve in small volumes>
Fish did not seem to be affected. I also have a basket starfish in
there, which fell from his favorite spot and died. So I immediately did
a 75% water change. The livestock is starting to do better(6 hours since
change). The only casualty seems to be the starfish :(.
Anyway, my question is....can you help me identify this Nudi and what he
<Not one I've see, photographed... and too lazy to get out my
references... see the works of David
Behrens, or spend a few hours on "SeaSlug
Is there anything else I can do to ease the stress on my tank from the
<Read on WWM re... can you see, use the search tool, indices?
Thanks for your help!
<Welcome. Bob Fenner>
Yes, and ID question.... sorry
You California guys have much info on this????
<What is that? Renilla? BobF>
Identification attempt for 3/27/13 creature
*Yes, and ID question.... sorry 3/27/13*
You California guys have much info on this????
<What is that? Renilla? BobF>
hello! I thought I might offer a guess as to what this creature might be. My
guess is that this is a Chiton, maybe
Cryptochiton stelleri; the colours and shape seem to match.
<<Ah yes Emilie. Please see LynnZ's input below. BobF>>
Hey Bob! I think the critter in question is Cryptochiton stelleri, aka
the Gumboot Chiton. Here's a link with a photo/info:
Hope that helps!
Nudibranch ID 1/11/13
Can you ID the attached pic of a Nudibranch? I believe it is the type that
eats Zoanthids, but I see no damage to any of my colonies and I found this
guy in the sump. Thanks!
<Mmm, yes... appears to be an Aeolid... do place the string:
"Aeolid predators of Zoanthids"
in your search tool and read re. Bob Fenner>
cropped and enhanced
|Re: Nudibranch ID
<Welcome Van. BobF>
Hermit Crab and Nudibranch: Clibanarius cruentatus and
Aeolidiella alba, IDs, comp. – 11/13/12
> <Hello, Lynn here this morning.>
> I recently brought 2 'Mexican algae hermit crabs' that were supposed
to be reef safe, one of them I cannot identify the species... Any idea?
> <Yep, it appears to be Clibanarius cruentatus, aka the “Spotted Black
Hermit crab”, which is in the family Diogenidae (left-handed hermits).
Whether this species is completely “reef-safe” depends on your
definition of the term. Hermits are typically omnivorous but can have
tendencies toward being either more herbivorous or carnivorous.
What's important is that if/when their preferred food dwindles, and they
get hungry enough, they will likely “sample” whatever else is available.
Bottom line: keep an eye on any and all hermits - even those labeled as
reef-safe, algae-eaters, or herbivores. That is, watch what they
tend to eat, make sure they have enough, and monitor for any damage to
livestock. It’s a good idea to supplement their food with meaty
bits of marine origin, sinking pellets, and/or bits of Nori (dried
seaweed sheets). Please see the following link for more
information and photos regarding Clibanarius cruentatus:
> More information on hermits here:
> Also found a Nudibranch on my live rock which I cannot identify.
He doesn't seem to have touched my corals.
> <That’s good to “hear”/read but do keep an eye on them as sometimes
the damage isn't immediately apparent. You have what appears to be a
species known as Aeolidiella alba (family Aeolidiidae). If you can get a
close look at the base of the rhinophores (the knobby-looking appendages
just behind the head), you should see either a fine reddish line, ring,
or splotch (see photos at links below for comparison). Also reported, is
this species’ odd appearance during locomotion as it “waves” or “jerks”
its cerata (appendages along the back) back and forth.
Unfortunately, I wasn’t able to locate any information regarding the
animal’s diet, but rest assured, it’s a carnivorous predator. These
Nudibranchs tend to hitchhike on or near their food source so if your
individual arrived on a recent coral addition, I’d remove it asap, and
keep an eye out for others.
> Please see the following links for photos and more information:
> More information on Aeolids here:
> Take care,
> -Lynn Z>
Re: Hermit Crab and Nudibranch: Clibanarius cruentatus and
Aeolidiella alba – 11/13/12
<You’re very welcome.>
..he came with my live rock which had 1 single Zoa and a single mushroom as
hitchhikers. I let the rock cycle and he is still alive and the Zoa and
mushroom are fine so I don't know what he could have been eating to live.
<Based on what seems to be the common theme within this family, I’d say a
Cnidarian of some sort. Every Aeolidiella species that I was able to find
diet-related information regarding, listed one/several varieties of anemone
as being their prey of choice. Interestingly enough, other genera within the
family (Aeolidiidae) listed hydroids and Palythoa in addition to anemones so
that adds to the list of possibilities. Whatever the prey, it’s possible
that there may still be some small/hidden individuals left that are
sustaining your Nudi. On the flipside, if it has already gone through the
food supply, you will likely see the animal roaming about the tank for a
short while, then one day it’ll just disappear. Take care, Lynn Z>
Re: Ahh, excellent as always. B – 11/13/12
Thanks Bob, it was a pleasant surprise to see that query in the inbox this
morning. I check in every day, looking for ID's but must be missing
At any rate, it's always a pleasure to see what neat little critters end up
in people's systems!
Take care and thanks again,
Nudibranch ID – 4/19/12
<Hi there, Lynn here this evening.>
Hopefully just a quick one for you.
<Heheee, I wish! That happens only occasionally when it comes to
Nudibranchs. There are simply too many species and too many
variations, etc., to have them all available in my head for quick recall.>
Can any of you correctly ID this Nudibranch species? It's baffling us and we
have scoured everywhere trying to look for something that it resembles. I
know it is difficult to see from the attached picture but it does have a
<I'm not sure what you mean by “crown”.>
…and rhinophores as not to be confused with an Aglajidae.
<Is there any possibility of procuring and sending along a few more photos –
or at least one that’s larger, showing more detail? Unfortunately, I
can’t see enough in the current one to narrow the ID with any real
certainty. Right now, I’m not sure if what you have is a sea slug,
Nudibranch, or even a flatworm of some sort. Offhand, I’d say it looks
a lot like a Nudibranch in the family Dorididae or Chromodorididae.
The general shape of the body and simple (as opposed to branched)
rhinophores are on target but I don’t/can’t see any gills that are typical
of these families. The gills, when extended, appear as a ring of
feathery appendages extending from the posterior dorsal/top surface of the
animal). Please see the following links for an example of a species in
each family (note the degree of variation in color/pattern):
If your animal does have the aforementioned gills, and you have the time,
you might try looking through the species list at the following link,
starting with the two families listed above, and see if you can find a
If the animal does not have those gills, and you’d still like to pursue an
ID, do send along another photo or two and we’ll try again. I’d also
need more information, such as size, where the animal originated, whether
you’ve noticed it feeding on anything in particular, and any other
descriptions or information that might be pertinent/helpful but not
necessarily visible in the photo.>
Many thanks once again
<You’re very welcome. Take care, Lynn Z>
Re: Nudibranch ID: Hypselodoris spp. - 4/20/12
Thanks so much for the speedy response and especially the links.
<You’re most welcome.>
We have come to the conclusion that it is definitely Hypselodoris infucata.
<Yay, we have a winner!>
It is exactly like the attached image. Although it is very small so
most likely to be a juvenile. What is their diet as I've been led to believe
they feed on sponges
<They do indeed. Their preferred prey is reported to be the species
(Is it reef safe)
<Depends on your definition, but everything should be safe except for the
...and also what is the likelihood of it surviving in an aquarium?
<Unfortunately, not much (long term), unless the sponge variety that it
feeds on is plentiful, or able to regenerate itself faster than it can be
consumed. Right now, it sounds like the little Nudi is fairly small so
there may be enough food around to sustain it. As it grows, however,
things get a bit dicey. This species reportedly gets up to about 55mm,
or around 2” in length, so as its size increases, so will its appetite.
More than likely, you’ll see the Nudi wandering around for a while then it
will simply disappear.>
<It was a pleasure, Si.>
<Take care, Lynn Z>
Mystery Invert 2/19/12
Hello WWM Crew,
I am sending you four jpegs of what I believe is some sort of
I don't know if it's a Nudibranch or a slug.
<All Nudibranchs are sea slugs, but not vice versa. This is a
member of the genus Phyllodesmium>
It was under a large hairy mushroom and I thought is was some
sort of tube anemone. I lifted up the mushroom to get a better
look at it, and some of the "cerata" (hope that's
came off the body. I used my high tech turkey baster and removed
it from the live rock. More of the cerata came off.
The cerata are kind of flat, and moved back and forth after they
detached from the body. I thought they may have been flukes or
some sort of salt water leech. I wasn't sure it was a
Nudibranch until after I watched and saw that it had a distinct
body and oral tentacles. Anyway, I have removed it from my
aquarium because I don't know what it is and it appeared to
be snacking on my mushroom.
<Could be. May need to be removed>
I really enjoy finding things in my aquarium, especially things
I've never seen before. I also took a video of it. I searched
WWM and the Internet for information and pictures of organisms
similar to this Nudibranch. I realize you are inundated with
requests for identifying organisms so any information you could
provide would be appreciated.
<And you, Bob Fenner>
Re: Need help with id
Sorry about that, I was doing a Google image search. Here is a
picture of the Nudibranchs in question.
<Neat! Looks like a member of the Eubranchidae, genus
Eubranchus... and a great mimic of the green algae Neomeris
There are two references on the page, and the information
contained isn't helping. The two are Nudibranch 8/16/07
Nudibranch, Sea Cucumber or Sea Slug? Aeolid Nudibranch
<Is this a close enough guess for you? Need to remove of
course if it is doing too much (predatory) damage. Cheers, Bob
Re: Need help with id 11/22/11
What do you mean by predatory damage?
<? What this species of naked gill slug eats, chews on>
What is it that they eat or do?
Is it reef safe?
<? Why are you writing instead of reading where you were
referred to? B>
Re: Need help with id 11/22/11
Didn't paste a referral. See here:
and the linked files above. B
Re: More Re: Need help with id, Nudibranch
I am sorry, but after 7 hours of reading and trying to figure out
what this is, I have no idea. I looked at the species you
mentioned and there is nothing that looks like it. Can you just
tell me if it is good or bad?
<... likely "bad" as in what is this animal eating
here? I would remove it if it is obviously doing too much damage.
Nudibranch, ID 11/11/11
Can you identify this type of Nudibranch for me? I have not been
able to find it myself. Also, is it safe for my reef tank? I have
only seen it twice, just on the glass.
<Mmm, no... this image is too blurry, poorly resolved. Need a
clear image of the dorsal surface>
<It may not be harmful; you'll have to keep an eye on what
it may be feeding on. Read here:
and the linked files above. Bob Fenner>
Nudibranch Identification 10/20/11
Hello WWM Crew!
First let me thank you for your invaluable service. I have found
the answers to virtually all of my reef aquarium questions (and
they are plentiful!) on your site, and have you to thank for my
thriving Nano mixed reef. On to the question. I recently had my
LFS order me a lettuce slug.
Expecting to see an Elysia crispata, I was surprised when this
creature was in the bag. I called the LFS and had them check
their manifest, and he was listed as an Elysia sp., but I
don't believe it. I believe it is a Nudibranch rather than a
slug, but after much searching on seaslugforum, I have not been
able to identify this guy. He is about 2 inches long, and I fear
that he is not the harmless herbivore that I was hoping for. I
know many of these guys have specialized diets, so I fear for his
survival as well as that of my tank if he is toxic. He is
currently in quarantine until I figure out what he is. Your
assistance is greatly appreciated!
<Since there are a gazillion species of Nudis, I suggest going
here to find a match.
I just do not have the time to go through all these.
Bob may have seen in the wild and/or may know and will input here
<You're welcome. James (Salty Dog)>
Re Nudibranch Identification 10/20/11-
Thank you for the link.
I was able to determine that this guy is a Ceratosoma
sinuatum, a sponge-eating species of Nudibranch with no chance of
survival in my tank.
I immediately found two other references to this Nudi being sold,
as mine was, as an Elysia crispata, or lettuce slug, so I thought
it might be a service to other perplexed readers to post the ID.
The distinguishing features are the white speckles both on the
"antennae" and the feathery gill cluster on his back,
the three "humps" on his back, the tallest being
nearest to the gills, and the broad lobes edging the mantle. They
come in many color variations, but usually have a green
background with yellow and blue speckles. At least one person
reported a distressed one oozing a white discharge, so I have
some concern about toxicity. Hopefully this helps someone else
out, although it would be better if no more of these poor
creatures are mis-collected!
<Thank you for this follow up, Jessica.>
<You're welcome. James (Salty Dog)>
Nudibranch? -- 02/04/11
Hey guys! As always, you guys rock!
I need some help identifying a Nudibranch/worm/slug... I've
never seen this one before. Any ideas?
<Looks to be an Aphroditid: http://en.wikipedia.org/wiki/Sea_mouse>
Tampa Reef Marine Management Services, LLC
<Welcome! Bob Fenner>
|Re: Nudibranch? --
Should I discard it? I found it in a Nano reef.
<... depends on what you have, what you're trying to do w/
"it"... See the Net re the life habits of this Errantiate
Polychaete family. B><<Don't tell John... but mainly
this family consumes other worms... Nereids principally,
|ID Please: Nudibranch, Possibly Melibe
viridis -- 8/5/10
Dear WWM Crew,
<Hello James, Lynn here today.>
I received this as a freebie from my LFS in Nagasaki, Japan. I have
no idea what it is and was wondering if you might shed some
<What you have is a neat little Nudibranch in the genus Melibe,
family Tethydidae. Without knowing where it originated, I can only
give you a best guess as to species. It looks most like Melibe
viridis, a potentially large (up to 12cm/4.72' long) species
with a taste for crustaceans. For more information/photos, please
see the following link:
It is 8 cm long. I've attached a picture as it looks like
something you'd find under a microscope.
Whatever it is, I'm not letting it near my H. kelloggi until I
know it's safe.
<Well, personally, I wouldn't add this to a seahorse tank.
Although Melibe viridis is a crawler that mainly eats crustaceans,
it can get fairly large. I'm not sure how large your H.
kelloggi individual is but I wouldn't exclude the possibility
of the Nudibranch coming across it while it's resting,
trapping, and ingesting it.>
<Take care, Lynn Z. >
Mysterious Creature 8/5/10
Hello Lynn, hello Bob,
There's a great mysterious creature question in the marine
inbox. I have NO idea at all what it is. Can't wait to hear
what you think.
Re: Mysterious Creature
I've seen one of these odd-looking creatures before.
It's a Nudibranch in the genus Melibe
possibly Melibe minuta
I just woke up, so as soon as I get some coffee in me,
I'll get the query written and sent on its way.
Take care and thanks again,
-Lynn The ones I've seen in N.E. Sulawesi, suck
up/vacuum muck... will attach pix. B
Yikes! What I still have a hard time grasping is
how it can consume sizable crabs without getting
nipped into letting go, or shredded. That oral
"veil" must be a lot tougher than it
Some are outright surprisingly LARGE! Have
"come across" species, specimens over a
foot in length. B Wow, how neat is that?
Great shots, Bob!
Mmm, well, wrong lens... 105
mm... and too short a focal depth/width...
<Well, I guess that just shows how much I
know...or don't know! I thought they
looked great. It's just such a
neat-looking creature. It looks like a
miniature version of some space monster from
the original Star Trek series.
but neat animal.
It had some commensal Hippolytid
shrimps "riding shotgun" on
it, neat as sunshine. B
<Oh wow, that is neat. I guess they
fed on whatever was stirred
up/dislodged as the Nudi foraged? See,
this is why I love ID work so much.
I'm not able to see all the neat
things you regularly observe in person
while diving, but this way I still get
to "discover", albeit
vicariously, some unbelievably neat
creatures. Thanks for sharing your
photos..take care, Lynn>
<Welcome Lynn. B>
Sea Slug ID: Likely Tritoniid Nudibranch -
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
(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
<There are an awful lot of Nudibranchs out there!>
Many thanks for your help.
<You're very welcome.>
Re: Sea Slug ID: Likely Tritoniid Nudibranch, now
Nephtheid - 5/24/10
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
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.
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.>
Was hoping you might be able to help identify the little critter
here. My nephew caught it in a bucket on Miami Beach. Thanks
<Is Glaucus..., an Aeolid Nudibranch; likely
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.
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
..and what looks like..a wilted flower the part of its body that
I assume is its anus or maybe 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
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
<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
<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:
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
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)
..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.>
<Take care, Lynn Zurik>
Nudibranch ID Link -- 02/08/10
FWIW, I came across this site today and found it pretty interesting,
especially with over 22,000 Nudibranch photos.
<More Nudi/es than many porn sites! B>
Nudibranch Photos to Share: Likely Tritoniid --
<Hello Lianne, Lynn here today.>
You are always sharing with us, thought you might enjoy these
This Nudibranch was sold to us as a small "sea hare"
(hare, hare, hare),
<Heeeee! Although it does bear a superficial resemblance to
the Blue-Ring Sea Hare (Stylocheilus striatus), that's not
what it is. Your little critter looks like a Nudibranch in the
suborder Dendronotina, family Tritoniidae. These creatures eat
soft corals, gorgonians, sea pens and possibly hydroids, have
distinctive 'pulpit' shaped rhinophores (sensory
tentacles on the head), as well as a number of branched
cerata/outgrowths that run the length of the body on either side.
They also have what's called an 'oral veil', a
multi-branched digitate flap that overhangs the mouth and can be
seen in your photos. This is used to detect/locate open polyps.
Unfortunately, I can't tell you what specie this is, but
apparently the blue spots I see on your individual are fairly
common in many of the Indo-West Pacific varieties. If you'd
like to pursue this ID further, please see the following link for
a list of species in the above-mentioned family (each is a link
with more information/photos). Be sure to note the degree of
color variation within each specie:
Stylocheilus striatus/Blue-Ring Sea Hare for comparison (note
difference in rhinophore shape, cerata shape/placement, etc.):
..and has shown a love of star polyp fronds (munch, munch,
munch). He only loves the flower, of course.
<Oh yes, Tritoniids love open polyps!>
Wondering if we could possibly meet his coral needs.
<That could get expensive!>
He is a big fellow, about 3 inches long.
<That's unusually large for a Tritoniid, but maybe the
animal's 3' all stretched out!>
At least it would be less expensive than feeding him Dendros!
<Heeee! It's undoubtedly a terrific and beautiful little
Nudi, but unless you have a very large population of expendable
polyps, I'd think about returning it for a credit/exchange.
By the way, thanks again for sharing the photos!>
<Take care, LynnZ>
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