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FAQs about Marine Snail Identification 30

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Related FAQs: Snail ID 1, Snail ID 2, Snail ID 3, Snail ID 4, Snail ID 5, Snail ID 6, Snail ID 7, Snail ID 8, Snail ID 9, Snail ID 10, Snail ID 11, Snail ID 12, Snail ID 13, Snail ID 14, Snail ID 15, Snail ID 16, Snail ID 17, Snail ID 18, Snail ID 19, Snail ID 20, Snail ID 21, Snail ID 22, Snail ID 23, Snail ID 24, Snail ID 25, Snail ID 26, Snail ID 27, Snail ID 28, Snail ID 29, & Marine Snails 1Marine Snails 2Marine Snails 3, Invertebrate ID, Snail Behavior, Snail Selection, Snail Compatibility, Snail Systems, Snail Feeding, Snail Disease, Snail Reproduction, MollusksSea SlugsAbalone

Snail Identification       2/5/19
Hi team,
Thanks for all the great work you do, I have learnt a lot from your site!
I noticed this white snail (see attached) about a month ago on my live rock and it has grown considerably quickly since. I have looked online everywhere and believe it may be a predatory whelk but I’m not too sure. Do you have any thoughts on what this snail may be?
Many thanks,
<Please crop, re-size your images to hundreds of Kbytes, and re-send.>
Re: Snail Identification       2/5/19

My apologies, I hope this image is clear enough / meets the size restrictions (362kBytes).
<Mmm; have you gone through the WWM SW snail ID FAQs?
Please do: http://www.wetwebmedia.com/snailidfaqs.htm
and the linked files above. Bob Fenner>

Fish eating snails     1/31/19
Good evening,
I was hoping you could help me identify a couple of different snails that I have in my tank. I thought they were Nassarius snails and I still think the 1 is but not sure of the other.
<The upper right one does look like a Nassarius species, the lower left, darker one, perhaps a Cerithid>
I have attached a close up of what I believe to be 2 similar but different snails. I know Nassarius snails will watch left over food but what concerns me is this morning I found about 8 or so chewing on the fins of a lionfish that was living but not dead.
<Mmmm; these snails didn't catch, kill the Lion>
I know they will consume a dead fish but I did not think they would attack one that was living. The lionfish has since died not sure if it was already dying or because of damage from the snails.
<The former; assuredly>
There are currently no fish and the tank will house shrimp gobies Dartfish and fairy wrasses that build a cocoon at night. should I be worried that they would go after a wrasse that was sleeping at night?
<I don't think so, no>
Thank Jason
<Thank you for sharing. Bob Fenner>

Id hitchhiking snail please      7/29/18
Hi Crew!
I found this very tiny snail on a liverock, it’s maybe 3mm long...could you please help ID? Thank you as always! I hope you have a nice day.
Dani ��
<Is this a Cerith/id? Bob Fenner>

Re: Stomatella? Hitchhiker ID on Ninja Star snail      7/7/18
Hello! Hmm, I’m not quite sure this is Stomatella anymore. It has not moved off the shell of the ninja star. Typically Stomatella I have encountered hide during the day. Here’s another pic, any ideas?
<In this sharper/closer image, looks like a snail of the Chilodontidae family, hope this helps. Wilberth. >

Mmm (RMF)

Stomatella or Scutus?       11/21/17
Hello wet web crew,
<Hey KL!>
I have looked over your site and read all your limpet and snail ID threads.
My main tank is 200 gallons with 75 refugium. Currently it only has crustaceans and soft corals in it. Mainly mushrooms and a toadstool.
I found this critter in my tank tonight and wondering what it is.
Looks like a snail but only a small shell. Is it a snail or a limpet?
What species?
<Yikes... due to striations on the shell, and that it isn't white... will guess a Stomatellid; but... could be either>
It's about 1 3/4 inch to 2 inches.
<The shell? Most Scutus top out at 12.5 mm>
Is it friend or foe?
<Friend; purposeful algae scraper>
I'm wondering if it felt safe to come out because there are no fish currently in the tank.
<Likely arose from your live rock; common>
It moves pretty fast for a snail. I also have video if you want me to send it.
It's shell seems frilled or scalloped along the edges and I can't really tell if its black or a translucent shell.
<Good points. Stomatellids typically have a mantle "tail" and are not emarginated>
Thank you for any help you can offer.
<I'd keep it. Cheers, Bob Fenner>

Critter ID       10/25/27
Hi there, I've got a funny little dude on one of my corals. I've asked every reefing group I can find and no one has an idea. It started off between these two heads of hammer coral and looked like a Chiton at first--it's a series of armored plates. Then it sort of curved as you can see here in the photo and it's growing fast. There are three of them now.
It is very, very hard--harder than the coral stalk and absolutely nothing budges it, even trying to slide a razor blade under the edge hasn't been successful. The picture below shows it just opened its 'mouth' end which is usually shut tight. Any ideas what it could be? I'd hate to kill it if it's a reef safe critter. Thank you!!!
<Mmm; can't quite make out in your pix, but would have guessed at first glance that these were Chitons as you mention, and with the clue that they can't be removed with a razor blade either limpets of some sort or, my final guess (for now) that these are a species of calcareous tube-building worm or snail. I would leave them here.
Thank you for sharing. Bob Fenner>

Conch eggs    4/13/17
Hello there,
I've had a conch in my sump for some time. He or she likes to bury in the sand but comes out to eat (it likes clams on the shell) and today I found 4 quarter sized egg casings on the side of the tank where the water cascades into the sump (fairly turbulent flow).
<These are them>
I can't seem to figure this out cause I only have one and I read that conchs fertilize the eggs internally.
<Yes; and are hermaphroditic>
If the eggs are not fertilized why does she lay them.
<Nature of the beast... like domestic chickens.>
I've had her for over a year and she is all alone bar a lobster but pretty sure he isn't the father :-). Attached are some pics. Can you please shed some light on this conundrum and also perhaps tell me what species she is?
<Can't quite make out from your pix, but maybe a Crown... Melongena corona>
<Welcome. Bob Fenner>

What's the verdict? Snail ID       4/11/17
Hi WWM Crew,
Can you please help me with a snail identification?
<Mmm; I think so. Is this a banded tulip snail?>

I’ve been seeing this hitchhiker every now and then since I put my new live rock in my tank last month. The tank is a 75 gallon with 30 gallon sump that will be a FOWLR for now and eventually morph into a reef with easier to care for corals (except I wound up with a hitchhiking Kenya tree coral so I guess I’m there already). Anyway, I’ve only seen this guy four or five times in the last month. He hides really well. I’ve looked through the snail ID FAQs, and seen several pictures that look like him. But sometimes the pictures are identified as harmful, and sometimes they are identified as something else that is not harmful.
<Is predatory if a tulip>
In short, I’m stumped on how to tell the difference. I’ve included three pictures, including one of his under side. As you can see from the pictures he is fat in the middle and conical in the front and rear. He has a stripped “trunk” that retracts in and out. He uses it to poke around the sand/live rock as he goes. His shell is about ½ inch long. What’s the verdict—harmful, helpful, neutral?
<Unfortunately, harmful>
As always, thank you so much for your help. I really appreciate your always being there for us.
<You're welcome. Bob Fenner>

Mystery hitchhikers on my frogspawn     2/10/17
Hello WWM crew!
I was referred here from Bayou Reef keepers by Jordan Stari.
<Ahh! Hi to Jordan. Hope to catch up with him at this year's MACNA there>
He recommended that I post this query specifically directed toward Lynn Z since she’s the invert expert. I have a mystery beastie on the base of two of my branching frogspawn heads. When they first showed up, they were so small I could barely tell they were something other than part of the coral. Then I started noticing they had kind of a corkscrew antennae or some other protrusion. I thought they might be some kind of Nudibranch, but even with a magnifying glass, it was difficult to pick out any distinguishing characteristics. I searched every site and message board I could find to no avail. They are right at the boundary between the soft tissue and the skeleton of each head and seem to retract into the soft tissue if I shine a light on them for more than a few seconds. When I got home from work today, one of them had come out far enough that it was ~1/2 – 3/4” long. I took some pictures, but only one of them is small enough in file size to comply with WWM picture requirements and it is hard to see anything on that one. I have attached it as a first look. If it’s okay, I would like to post the best quality picture that shows it pretty well.
Please let me know if that is ok.
<Yes; though; I don't see what you're referring to. Lynn?>
I have had these corals for about two months and they have grown probably 2-3 times the size they were when I got
them in that time. Two of the heads have begun to split. Until about 4 days ago, all seemed to be well. All of the corals in the tank have been given a 10 minute CoralRx Pro dip before being placed in the tank. I’m thinking that since they emerged from within the soft tissue, maybe they were there from the beginning and survived the dip.
In the pic, the dark vertical shape on the left is the branch of the skeleton. The offending beastie is the whitish thing running parallel to the branch (it is roughly ½-3/4” in length). As I said, I have better pics, but did not want to run afoul of the posting rules.
<Do post elsewhere on the Net and send along links please>
Please let me know if you know what this is, whether I should worry about it, and how I can get rid of it if necessary.
<Like grading school papers, "When in doubt, count it out", I'd vacuum, remove this>
Thanks in advance for the help!
Kevin Drane
<Have sent on to LynnZ for her input. Bob Fenner>


Re: Mystery hitchhikers on my frogspawn - 2/11/2017
Thanks for the quick response. I have a couple of pics posted on the Bayou Reefkeeping forum. Here's a link:
Euphyllia eating Nudis?
<Mmm; the little white bits right? I don't see rhinophores, gills on these... Look more like Scutus... a snail on what little I make out... white shells (could be overgrown), and black feet... No way for you to remove, shoot and send a better close up pic?>
It seems to be hiding within the soft tissue of the coral because there are times when you can't see it at all and then it just appears. Thanks again for the help!
<The better pic please. Bob Fenner>

Re: Mystery hitchhikers on my frogspawn - 2/11/2017
Actually, the long white thing that is extending down from the base of the soft tissue is one organism. The white bits are part of it.
<Don't see it mate>
There is no shell and it's all white. While it was extended out like that last night, I tried to suck it out with a turkey baster and it held fast. I then tried grab it with some tweezers and it still wouldn't come loose. It ended up breaking in two. The part that was still attached retracted up into the coral's soft tissue and I haven't seen it since. The part that broke off
kind of fell apart and the pieces were very small helical bits maybe 2-3 mm long. My fire fish ate ended up eating the pieces. Now I'm worried that it is going to die inside the soft tissue and as it rots will poison the coral. I'm debating whether I want to break the heads free from the rock and dipping them with Bayer.
<Have you considered fragging this colony? I might. B>
Re: Mystery hitchhikers on my frogspawn - 2/11/2017

Thanks for the quick response.
<<Hi Kevin and Bob. Sorry I’m a late arrival on this topic!>>
I have a couple of pics posted on the Bayou Reefkeeping forum. Here's a link: Euphyllia eating Nudis? http://www.bayoureefkeeping.com/forums/topic/16109-euphyllia-eating-nudis/#comment-191958
<Mmm; the little white bits right? I don't see rhinophores, gills on these... Look more like Scutus... a snail on what little I make out...white shells (could be overgrown), and black feet... No way for you to remove, shoot and send a better close up pic?>
<<Unfortunately, I can’t see enough detail in the photos to determine exactly what the subject is either. Offhand, it looks like a typical looping mass of Cerith snail eggs - I’ve seen these before on Euphyllids. Please see the following link for an example (bear in mind that these looping masses can be variably arranged): http://www.nano-reef.com/topic/270550-whats-on-my-frogspawn/ . Do you have any of these snails in your system? If so, and this is an egg mass, the multitude of loops should start breaking up and detaching within a few days.>>
It seems to be hiding within the soft tissue of the coral because there are times when you can't see it at all and then it just appears.
<<If this is an egg mass, perhaps it’s acting as an irritant? Honestly, I’m not a coral expert so I’m not sure if it’s possible for the soft tissue on a Euphyllids stalk to react by trying to alternately envelop then repel an irritant.>>
Thanks again for the help!
<The better pic please. Bob Fenner>
<<You’re very welcome. I just wish I could have given you a concrete answer. Ditto what Bob said regarding a photo (if possible!). Take care, Lynn Zurik>>
<Thank you Lynn. B>

Re: Mystery hitchhikers on my frogspawn: Mesenterial Filaments - 2/11/2017
<Greetings, Kevin>
I do not have any Cerith snails
<There goes that theory! On the plus-side, I believe I have an answer for you.>
and I've never seen snail eggs move around like this.
<No, any movement would have to have been caused by something else: water current, hatching individuals, instability/movement of whatever the mass was deposited upon, or perhaps a critter of some sort wriggling about inside the mass.>
Unfortunately, I can't get another picture because after I tried to pull it off, it retracted back up into the soft tissue of the coral.
<Yep, this is normal (see below).
There is no question in my mind that it is some kind of separate organism. I have posted another picture to the forum- this time with annotation.
<Yes, I see – thanks. After thinking about this a bit more this morning, I started wondering if what we were seeing was simply part of the coral itself, and that was the ticket. All those loopy structures (that look like guts) did indeed come from inside the coral. They’re mesenterial filaments that, thanks to stinging cells/nematocysts, are used to capture/digest, as well as fight off any threat/intrusion into a coral’s “space”. It could be that the coral detected a threat (physical or chemical), and deployed the filaments. I see a small collection of vermetid gastropods to the left of the filaments that may be at least part of the issue. Vermetids send out sticky strands to catch food particles that drift by. Those strands could be contacting the coral’s soft tissue and irritating it. I ran across a photo at WWM that looks very similar: http://www.wetwebmedia.com/carydisf7.htm . Please see the query at the bottom of the page titled “Worm infestation… no -12/28/2007”, as well as a WWM search for mesenterial filaments, Vermetids.>
I appreciate the time you have spent trying to help me.
<No problem, I hope this helps. By the way, if you decide to get rid of the Vermetids, you can do so my either breaking them off with tweezers at the base (do not use bare hands – the tubes are brittle and very sharp!), or seal the tube openings with some gel-type Cyano glue.>
Hopefully the new picture will help you see it better.
<I think we’re good to go! Take care, Lynn Zurik>
Thank you Lynn. B <Always a pleasure, Bob!>
Follow-up Re: Mystery hitchhikers on my frogspawn: Mesenterial Filaments - 2/11/2017

Awesome! Thanks for the diagnosis.
<You are most welcome.>
Jordan was right that you know your stuff.
<Well, we all learned something this time! All I knew was that things weren’t adding up, critter-wise, so I followed a hunch and it paid off.>
You just saved the coral from the trauma of being broken off the rock and dipped again.
I just knew it was some kind of parasite.
<I can certainly understand why.>
Unfortunately, in my haste to keep a parasite from harming my coral, I tore some of its mesentery trying to remove it. Hopefully it recovers!
<I would think so.>
It all makes perfect sense now that I put all the pieces together. They had (very small) Vermetids on them when I bought them as frags. The coral and the Vermetids have both grown considerably since I got them.
<Yay, regarding the coral! As for the Vermetids, they thrive/multiply in high nutrient conditions so do keep an eye on this. Same goes for what appears to be some Spionid or Chaetopterid worms to the right of the mesenterial filaments. In silhouette, you can see a number of paired feeding tentacles (“palps”). Although not visible in the photo, these palps extend from hardened mucus tubes covered with sand grains, bits of substrate, and/or shell. These worms are typically harmless/beneficial particulate feeders/detritivores but when numerous can irritate corals, particularly Zoanthids.>
In the last couple weeks, the coral has not been extending as much as it had been. Now I realize it was due to the Vermetids growing as much as they have. I will try scraping them off now that I know they are causing irritation.
<Good idea. Just be careful. You do not want to get a nasty infection after cutting yourself on those sharp little shells!>
Thanks again!
<It was a pleasure! Take care, Lynn Zurik>

Marine slug question      1/25/17
Hey I am wondering if you can help me identity a small yellow slug I found in my tank there are lots of them and how I may be able to contain them.
Sent from my iPhone
<Can you crop, optimize and re-send, or make better pix... of a total of a few hundred Kbyte size? Bob Fenner>
Re: Marine slug question      1/25/17

Sorry I'm not sure I understand why you mean. Just a clearer picture or more zoomed as well.
<Bob's on his travels to the tropics, visiting our underwater pals. But that means viewing large image files is a chore when he's basically stuck with Internet access marginally better than dial-up. If you can help him out by resizing images so they're no bigger than, say, 500 kH in size, that's great. Online tools such as this one are useful if you don't have
image editing software to hand...
Cheers, Neale.>

Re: Marine slug question    1/26/17
Sent from my iPhone
<? May be a Tylodina sp. as juv.s. B>

Re: Marine slug question      1/28/17
Is this a parasite?
<? Nope>
If yes do you have any suggestions as how to rid them.
<See WWM re such Gastropod Compatibility. The FAQs mate. B>
Thank you very much I am truly grateful!!!

Murex snail confirmation      12/11/16
Is this a murex?
<Appears to be to me>
Fits the description of knobs however appears to be much shorter than what pics are showing.
<Can be larger when specimens are young, small>
<Search WWM re Murex/Muricid Identification. Bob Fenner>

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