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FAQs about Marine Snail Identification 25

Related Articles: Gastropods, Sea Slugs, Mollusks, Abalone,

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 26, & Marine Snails 1, Marine Snails 2, Marine Snails 3, Invertebrate ID, Snail Behavior, Snail Selection, Snail Compatibility, Snail Systems, Snail Feeding, Snail Disease, Snail Reproduction, Mollusks, Sea Slugs, Abalone,

Nassarius snail ID and a quick <fdg.> question  9/5.5/11
I've had this snail for a while in my tank and have had no problem with it but I'm wondering if it really is what it was sold to me as or not. I was told it was a Super Tongan Nassarius, but I've never seen one that looks like this and I'm hoping it's not a whelk (which I've heard are not reef safe).
<Mmm, no... tis an Ilyanassa/Nassarius sp.>
My next question is, assuming that it's an ok snail, should I be supplementing feeding?
<Not likely, no>
It has been with me for about 3 months and I have not so far, but this is a Nano tank so I'm concerned it might not be getting enough food and that I might be starving the poor thing. It doesn't come out very often except feeding time (and even then sometimes it doesn't bother coming out), which I believe to be typical of Nassarius. I do have detritus in the tank in some spots (like most tanks) and have heard that Nassarius target it, yet I never see it come out to eat it. Any idea why? Thanks! :-)
<Please read here:
Bob Fenner>

Another Live Rock Hitchhiker ID   5/15/11
Dear Crew,
Thanks so much for your time! Just a quick ID today.
I noticed several of these organisms upon viewing my reef this evening. The tank has been set up for several years and has seen flatworms, bristle worms, and Aiptasia among other pests, all which have been easily managed thanks to WWM!
I've never seen anything like these and they have seemed to have just popped up.
Nothing new has been added to the tank in 7 or 8 months.
They seem to have a mucus foot, and tiny shell, and two clearly identifiable antennae. They look like baby snails. The one on the top is actually two that are in close proximity. I'm sorry about the pic quality- these boogers are tiny, perhaps 1 mm or less.
I've not read much about snail reproduction evolving beyond the egg stage in home marine aquaria and therefore doubt that's what these guys are.
Any ideas? Friend or foe?
<Are these actually moving? To me they look like small Syconoid sponges.
Please see the Net, WWM re. Bob Fenner>

Re: Another Live Rock Hitchhiker ID    5/15/11
Thank you Bob!
<Welcome Joe>
I really appreciate your time! This is a busy month for you!
<Don't know what I'd do if I had a real job!>
These are definitely moving. The pic was taken of the ones that are crawling on the aquarium glass. I did some posting on our local forum and a couple of folks thought they look like Collonista snails, which they indeed do.
In any event, I doubt that they are any harm to the reef.
<As long as not too many in number...>
Thank you again, enjoy yourself, and as always, stay safe!
<Thank you. Cheers, BobF>

Snail ID Request -- Whelklets in My Nano? Yes! 3/30/11
<Hello Ken, Lynn here today.>
I've recently discovered two small snails in my 14 gal. Nano reef tank that look like they might be bad guys.
<You'd be right!>
After searching a variety of Web sites, including the generous amount of wonderful info on WWM, my eyes have crossed and I've decided to appeal to the experts. What might they be?
<They're whelks of some sort (family Buccinidae, subfamily Pisaniinae). Do you know where they originated? If it was from around Florida, they're most likely one of the following species: Gemophos tinctus (the Tinted or Painted Cantharus), Gemophos auritulus (the Gaudy Cantharus), or something like Engina turbinella (the White-spotted Engina/Spotted Lesser Whelk). The Gemophos species both have mottled shells of varying color and the same spotted/mottled soft tissue I see in one of your individuals. Unfortunately, I can't find a good photo of the soft tissue of E. turbinella for comparison. Beyond that, the ID is complicated by the degree to which each species can vary in color, pattern, and shell structure. For example, Engina turbinella can appear heavily spotted or thinly banded. I'd need detailed, close-up photos (especially of the lip area/aperture), and the location of origin, in order to proceed further.>
Will they get huge, or stay small
<If they're one of the Gemophos species, they can reach a maximum shell length of ~1.25'/32mm (G. tinctus) to ~1.4'/35mm (G. auritulus). Engina turbinella, on the other hand, tops out at a diminutive .6'/16mm.>
..and cute?
<Definitely! I think they're neat-looking little snails. It's just a shame they're not good candidates for a mixed reef system.>
Are they killers, or star Hoovers for the clean-up crew?
<Heeeee! These snails have the potential to be star Hoovers *of* the clean-up crew! They're opportunistic, carnivorous predators and scavengers. Unfortunately, I don't have any details regarding the specific diet of Gemophos auritulus or Engina turbinella, but I can tell you that although Gemophos tinctus has a preference for sessile invertebrates, it will also prey on other snails and bivalves. Trust me, I've seen it first-hand! The bottom line is that I wouldn't trust any of these species around other snails. For more information/photos on these species, please see the following links:
Gemophos tinctus: FAQ titled 'Snail ID: Predatory/Scavenging Whelk -- 2/12/10' (refer to links within as well): http://www.wetwebmedia.com/WhelkF.htm?h=
Gemophos auritulus: In situ: http://www.jaxshells.org/2295anne.htm
http://www.gastropods.com/7/Shell_1927.shtml >
Engina turbinella: http://www.gastropods.com/4/Shell_1924.shtml
http://z14.invisionfree.com/Conchologist_Forum/index.php?showtopic=1908 >
I've attached two pictures showing tops and bottoms.
<Thank you! Good photos make all the difference when it comes to ID work.>
The shell of the larger snail is about 1/4 inch long. I currently have them quarantined until I can figure out if they are safe to keep. Please advise: should they stay, or should they go?
<They should go 'or as Arnold would say 'Hasta la vista, baby'. You could always set them up in a separate Nano system if desired. Just offer meaty bits of marine origin (fish, clam, squid, etc.) or possibly sinking pellets designed for shrimps, crabs, and the like.>
Thanks for your help, and for all the great work you do to maintain this amazing Web site!
<You're very welcome and thank you!>
<Take care, Lynn Z>

Snail Problem. Need Help Identifying and Removing -- 3/6/11
Dear Bob & Group,
<Hello Pritesh, Lynn here today.>
I have this big problem of snails in my Saltwater Aquarium; it looks more like a snail tank and less than a fish tank. :D It's a FOWLR type of setup.
<What size tank?>
I have 3 Fish in the tank as of now. A pair of Nemo and a Pakistani Butterfly Fish.
So now about my problem. I have a major outbreak of snails in my tank. I am attaching few photos with this email that should help you identify the type of snail.
<Unfortunately, I'd need a bit more information (size, where the snails originated) and close-up, detailed photos in order to supply an ID. I can tell you though that whatever it is appears to be some sort of algal grazer.>
I want to get rid of these snails. There should be more than 500 small snails in my tank now.
Please suggest me some fish which would eat these snails (should not bother existing fishes) or some way of getting rid of them.
<I would opt for thinning them out a bit, via manual removal, and keeping the remainder on hand as part of your clean-up crew. (Bob, do you have any input here re: possible predators?)<<<Not w/o knowing more re the size of tank, other livestock. RMF>>
Resized the images as you told.
<You're very welcome.>
<Take care, Lynn Z>

Predatory Snail Problem -- 1/30/11

<Hi there, Lynn here today.>
I am having a problem with some predatory snails in my marine tank.
There are two types: one looks like a dove snail, but when it gets near to a dove snail it chases it. When it is close it looks to stab it causing it to fall off the tank glass. It seems to have recovered but I'm finding a lot of empty dove snail shells.
<There are a number of possibilities as to the culprit, but it sounds like some sort of predatory Whelk or possibly a Murex. In order to narrow things further, I'd need a couple of photos and a bit more information (where the snail originated, size, along with any other observations not visible in the photos). If possible, when taking the photos, try to get two shots from above, each showing the length of the shell (at least one showing the side with the opening). This is a whole lot easier to do if you can remove the snail to a bowl of SW. If you're unable to do this, just do the best you can with a photo or two of the snail while it's still in the tank.>
The second is white in colour and hides in the gravel. It is larger, about 1" long, and I have only ever seen it eating mussel meat and a fish I lost after being stung by one of my anemones. Is this likely to be predatory or just a scavenger?
<It could be both. Again, there are numerous possibilities. You could have a scavenging Nassariid (family Nassariidae -- includes Nassarius spp. as well as the often light-colored Bullia spp.), some sort of Olive snail (family Olividae), or something else entirely. If possible, please do send along some photos and a bit more information. Hopefully the combination will enable me to give you a better idea as to what you're dealing with. By the way, if you're unable to send photos, and decide to leave the snail in place, be sure to keep it well fed with meaty bits of marine origin such as fish, clam, shrimp, squid, etc., and keep an eye out for signs of predation.>
Is there a way I can remove the snails that are feeding on the dove snails?
<I'd opt for physical removal on sight. I'd also recommend periodic checks at night after the lights have been out for a bit.>
Thanks in advance
<You're very welcome.>
A Reid
<Take care, Lynn Z>

Collonista pic 1/21/11
Hi WWM crew...thought I'd share my first non-fuzzy pic of a Collonista in my tank. He was nice enough to perch on an outcropping of LR that is very close to the front glass. I noticed him because he was 'blowing smoke' - sperm cloud I presume. That's when I realized he was probably not a baby Turbo, but a mature Collonista (he's about 1/4 inch diameter).
Thanks for all your invaluable help and information!
<Thank you for sharing Tommy! Bob Fenner>

Mystery Mollusk 1/17/11
Would love it if anyone can point me in the right direction on an ID for a hitchhiker that came in with one of my Zoa colonies. I think it's a mollusk...I've had trouble putting together a good enough description of
this thing to generate a proper search string. I've scoured photo ID pages of mollusks and gastropods, but I don't know if I'm even on the right trail.
<Mmm, I think I see what you're referring to... have cropped the middle image you sent along... see the Daily FAQs re... This is a Vermetid Snail:
This little guy is only about 2-3mm in diameter. He is embedded in a rock that houses a Zoa colony, and seems to be permanently attached. Hasn't changed location since I got the rock/colony about 5 months ago. He has a radial disc-shaped top shell that is reddish-brown and looks like an operculum of some
kind with a hole or depression in the center, and he can withdraw and seal himself shut with it.
<Good clues, description>
When he pops open, there's a soft body that looks sort of like a tiny snail, and I count 4 tentacles, 2 very short and 2 longer, one of the longer ones about 3 times as long as the other, stretching to about 5 mm.
His behavior is the most peculiar thing about him, and what made me notice him to begin with. He seems to feed by spooling out a long strand of mucus as a fishing line, and then slowly reeling it back in a mm or so at a time.
At first I thought it was a secretion from the Zoas, but it is just a single thread that traces back to this guy, and he does consume it as he reels it in. In fact, sometimes he 'catches' one of the Zoa polyps and bends it back up towards him, but he doesn't seem to do any damage, it just gets released once he pulls the thread back in.
<Not problematical>
The hole in the shell had me thinking keyhole limpet from some pics I saw, but it sounds like those are bigger and more mobile and snail-like. I then found a description of Limacina helicina that described what sounded like a similar mucus-fishing behavior, and pics look a little similar (though transparent), but
that sounds like it's a free-floating snail or jellyfish of some sort (http://jellieszone.com/limacina.htm). I also wondered if it could be some kind of barnacle, but haven't seen any mention of these in my searches.
It's proven difficult to get a clear photo of this guy due to his size, but I've attached a few small ones that are the best I've been able to do. Any help you can provide is greatly appreciated!
San Francisco
<Do see my pix on the citation and the linked files (above) re this family. Bob Fenner>

Re: Mystery Mollusk
That's the critter! Thanks very much, good to know he's not a threat.
More reading to do now...
<Ahh! B>

help id this hitchhiker 1/6/11
Hi guys and gals at WetWebMedia
<Howdy Sujan>
Greetings from South Africa.
<And back at you from (today) sunny Southern Cal.>
As always thank you for your past help in identifying the various critters I have found on live rock.
Can you please help identify this creature which appears to be some sort of slug or Nudibranch? I am hoping it is not harmful.
<Mmm, is a gastropod... likely a Limpet... see the genus Scutus on the Net. Not generally harmful>
It's about 1.5 inches and moves quite quickly. I have mainly Indonesian live rock in my tank and the only recent addition has been some Zoanthids and a pagoda coral.
I am thinking that it probably came into my tank with the more recent additions.
<Likely so>
thank you very much for your help.
<Welcome! Bob Fenner>

Re: help id this hitchhiker 1/6/11
thanks, Bob :) You are really quick to answer. Almost like a doctor that does house calls... only much, much better.
<Heeee! At least no gagging tongue depressors!>
All the best for the new year :)
<And you my friend. BobF>

Possible ID please? snail and crab 11/13/10
Greetings to you and the crew,
Once again I find myself relying on your expertise to sort out the miss-information I've gained through my research attempts.
The snail I have come to believe could be a whelk of some sort... but have also researched that since this shell does not display a body two times longer then the spire, so it isn't.
<Mmm, give a read here: http://reefkeeping.com/issues/2005-11/rs/index.php
Unfortunately, I can not confirm where the little guy is from. All the live rock is about a year or more old and was touted as a combo of Fiji and Florida, with any frag/coral spending 8 to 10 weeks in isolation minimum... so I actually have no idea how long it has been in there. I have him in a container with a small piece of krill mash hopeful to observe it eat as I have read that whelks can/do not eat algae - but apparently being captured has put off his appetite. Could you possibly confirm what he is please?
<Likely a Conch...
On a side note - could it be the reason for the die-off on the Monti?
<Mmm, not at all likely>
The crab was found on a piece of Haitian rock (still in isolation) and I am thinking Mithrax...
<The genus? Nah>
'cept I can't find any as fuzzy or grainy as he is. Of course, there isn't a wealth of 'identified' crab pics out there either:) Another description leans towards
a Black-Finger Crab, but they generally do not show/have fuzz. Presently he resides in a 3L Nano cube (no... not a typo) with chelto (spelling?) left in at all times, Nori, veg and meat flakes, and krill. I can't verify which he is eating. Again I ask... Can you ID please?
<Not from this pic, no. Bob Fenner>

Need help id snail, need better pix 10/27/10
hey guys,
<And gals>
I am having this problem in my SALTWATER AQUARIUM. I am having a snail outbreak and I am unable to identify which snails are they.
daily I have to remove at least 20 of these snails.
I am attaching a photo of the snail. the photo is not that clear cause its taken from a cell phone cam.
<Too blurry to be of use. Peruse here:
and the linked files above. Bob Fenner>

R2: Nassarius Snail Question/Amphiprion Cross-breeding (and now, snail ID) - 09/01/10
Hi Eric,
<<Hiya Chris>>
I have attached a photo of the snails that have been showing up in my aquarium - in the various sizes that I have noticed.
<<Ah yes'¦ These look to be a species of Nerite, or maybe a Collonista species (take a look at the operculum covering the shell opening--Collonista spp. have a prominent 'pit' in the center). Either way, nothing to be concerned with>>
Just a few questions - does it at all look like any of the conch eggs could have survived?
<<No--these are not Conchs>>
If not, is this a snail that you readily recognize and under the circumstances would you still consider it harmless or even beneficial?
<<Yes (well, as stated at least) and yes>>
Thanks again to all for the expert direction!
Chris K
<<Always a pleasure to share, Chris'¦ Eric Russell>>

Snail Overpopulation: Likely Juvenile Ceriths - 8/26/10
Hello once again WWM crew.
<Hello Miguel, Lynn here today.>
Have you ever had one of those sleepless nights and you just wondered what was going on in your tank and you take a peek?
<Oh yes.>
Well I had one of those a couple of nights ago and decided to check in on my reef tank. I'm glad I did because I noticed a Teddy bear crab munching away on a lord coral frag,
(I was fortunate enough to just pick up the frag and dump the crab into my refugium)
<You were very lucky indeed to have been able to catch it that easily.>
.. but I also noticed hundreds of small white snails all over the LR. I had seen a few of these small snails during the daytime and I just thought they were baby Cerith snails.
<They could be either juveniles or some other species entirely. Chances are good that they're harmless. There are quite a few small, white(-ish), beneficial herbivores. I'd need to see a couple of high resolution, close-up shots (one taken from above the snail, the other showing the opening) to have much of a chance at an ID. >
I had also seen what I thought were immature Cerith snails which were black with a white tip. I started looking for an I.D and along the way someone mentioned pyramid snails.
<Yikes, you don't want those. Thankfully, I doubt that's what you have. Pyrams are typically very small (less than 5mm), and white to a light brown/tan in color. They don't have the strongly demarcated white/dark brown/black shells like I see in your photos. Please see the following link for more information related to distinguishing Pyrams from other harmless snails such as Rissoids: http://www.reefland.com/articles/rho/identify-this-rissoid-and-pyramidellid-snails >
Do Ceriths start out white? Or do they start with the same colors as the adults?
<To be honest, I'm not sure. I haven't seen any white juveniles (of normally dark-shelled species), but that doesn't mean they're not out there. >
Enclosed are a few pictures. The first one is comparing a Cerith with the largest of what I'm calling the "immature Cerith".
<I'm pretty sure that's a Cerith of some sort. It's a shame the large individual's shell is covered with so much coralline. There's no way I can compare the surface texture of the two.>
The second one is of two sizes of the "immature Cerith?"
<This one threw me for a bit because the shells appear stockier than a typical Cerith. Thankfully, they look enough like the snail in photo 1 that I think it's just an issue of viewing angle. If I hadn't seen that first individual, I would have looked into the possibility of a Nassarius species or perhaps a whelk in the genus Pollia, Gemophos, or Cantharus. I don't think it's any of those, though. I don't see any long siphons (typical of whelks and Nassarius spp.) and the combination of surface texture, color, and proportion isn't quite right. The more I look at all of the individuals (excluding the white ones), the more I think that what you're seeing are juvenile Ceriths. If I had to guess, I'd say they're probably Cerithium lutosum (aka the Dwarf Variable Cerith), due to shell texture, whitish tips, and the fact that they reproduce well in aquaria. Naturally, I have to throw in the caveat that there are many Cerithium spp. out there, along with several closely related genera, so the possibilities are many. The bottom line is that I don't think you have anything to worry about. >
..and the last one there two of the small white snails (9 and 3 o'clock)
<Again, these could be very young snails or something else entirely. Whatever they are, chances are good that they're harmless.>
..and two of the black/white snails (11 and 6 o'clock). Do I need to be concerned about these snails if they are not Cerith?
<I wouldn't be, not unless you're noticing damage/injury to livestock.>
And if they are not Cerith, any idea as to what they are?
<There are many possibilities. I'd need some good photos and a bit more information (how big they are and where they originated, if possible). Please see the following links for comparison:
Cerithium lutosum: http://www.gastropods.com/0/Shell_2560.shtml
More Ceriths: http://www.gastropods.com/Taxon_pages/TN_Family_CERITHIIDAE_CERITHIINAE.shtml
Gemophos, Pollia, Cantharus, for comparison: http://www.gastropods.com/Taxon_pages/TN_Family_BUCCINIDAE_PISANIINAE.shtml >
As always thank you for your help in all these fishy matters,
<You're very welcome.>
Miguel Miguel
<Take care, Lynn Z>

Re: Snail Overpopulation: Likely Juvenile Ceriths - 8/28/10
<Hello Miguel.>
Thank you for the reply Lynn Z.
<You're very welcome.>
It is time to get the macro lens out and take better pictures and forward them to you.
<Sounds good.>
As to the origins of these snails, the stockier black and white snails (and the small white snails) started appearing after I added some Chaeto to the refugium.
<Thanks, all information is useful.>
I personally did not add them to the main tank but they are there now.
<You purchased Ceriths though, right? If so, do you know the species, or even the common, name? If not, be sure to include a photo of one (whichever has the least amount of coralline covering the shell).>
I imagine they got pumped into the main tank from the refugium. The mouth piece of the stockier, black and white snails are identical to the Cerith, no long proboscis.
<That's good to know, thanks.>
Anyhow, I will try to get higher resolution pictures to you to try to figure out what they are. BTW, so far I have not seen the small white snails bother the corals...yet.
<I doubt you will. If they were coral predators (like Epitonium spp./Wendletraps), they'd be all over their coral of choice and if they were Pyrams, they'd be after your snails (especially Astraea/Lithopoma spp. or clams). Honestly, I think these snails are nothing to worry about, but I'm more than happy to take a look at any photos just to make sure!>
Thank you for your help,
<It's a pleasure.>
<Take care, Lynn>

Unknown Critter ID? Snail - 8/23/10
<Hello Penny, Lynn here this afternoon.>
Got another hitchhiker snail that I can't ID. Good or bad guy?
<Hmmm, I'd love to help, but I need a bit more information and a more detailed/larger/higher resolution photo. By any chance, do you know what part of the world the snails came from? Did they hitchhike in on a particular coral and if so, what type? Also, what's the size? Any and all information you can supply will be helpful. Right now, I can't tell if what you have is some sort of Olive (family Olividae), a juvenile Cowry (family Cypraeidae) or something else entirely. Whatever it is, it's pretty but I'm betting that you'd like a bit more information than that!>
Thanks in advance for any help!
<Unfortunately, I can't offer much now, but hopefully that will change with the above info and another photo!>
Penny Harkins
<Take care, Lynn Zurik>
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