Please visit our Sponsors

FAQs about Limpet Snails, Acmaeidae, Fissurellidae and more, Scutus, Stomatella
Compatibility, Control 

Related Articles: GastropodsSea SlugsMollusksAbalone

Related FAQs: Limpets 1, Limpets 2, Limpets 3, Limpets 4, & Limpet Identification 1, Limpet ID 2, Limpet Behavior, Limpet Selection, Limpet Systems, Limpet Feeding, Limpet Disease, Limpet Reproduction, & Marine Snails 1Marine Snails 2Marine Snails 3, Marine Snails 4, Snail ID 1, Snail ID 2, Snail Behavior, Snail Selection, Snail Compatibility, Snail Systems, Snail Feeding, Snail Disease, Snail Reproduction, MollusksSea SlugsAbalone


Limpet Infestation     4/22/13
<Hey Matt>
I have a 200 gallon Acrylic fish keeper system that I have been using for my saltwater business. At some point, I mistakenly added a piece of Live Rock to the system which ended up releasing a few Limpets into the bioball system and rest of the tank. Now I am confronted with causing scratches each time I need to clear algae away with nylon pads. The limpets get caught in the pad and scratch right along the acrylic panels every time I clean. They even hide in the corners of the acrylic cubes and I do not the scratches they are causing.
Before I added that live rock, cleaning was a breeze with no fear of picking up any abrasive shells or limpets. My question is: Can the limpets be killed off by dosing the system with something?
<They can... there are pretty non-specific molluscicides... like copper compounds. Trouble is, they'll take most all invertebrate life with them...
You can't effectively remove all live rock... as this will re-introduce the Limpets... There are some fishes that notably consume such. Search on WWM re>
Or does the entire system have to be dried out and started over? Or use chlorinating freshwater to kill them off. They are all over my bioballs and all other surfaces in the system.
Thanks for your help.
<Welcome. Bob Fenner>

Keyhole Limpets and Other Snails, repro., comp. -- 3/10/11
Hi Crew,
<Hello Sam, Lynn here today.>
I have a 24 gallon Aquapod. Among my critters is a pair of Keyhole limpets that I bought about 2 years ago. I now have a few dozen babies and am curious as to how they manage to reproduce.
<It varies, but typically they broadcast gametes (sperm and eggs) into the water column. Interestingly enough, some actually brood their young.>
I seem to find the babies in the most unlikely places like in my hang on skimmer.
<Yep, I can tell you from personal experience that they also like hang-on filters! Judging from the fact that these limpets reproduce successfully in home aquaria, they more than likely have a very short free-swimming larval stage. Many likely perish during this period due to equipment issues and predation. However, the lucky ones find sanctuary in the relative safe haven of skimmers, filters, fuges, and the like. There, they find an environment with sufficient food to entice them to settle and metamorphose into tiny replicas of their parents.>
They grow very slowly.
<Yes, they do -- or at least mine seemed to.>
My first set of babies are still about half the size of a split pea. Aside from the fact that they are very difficult to remove as compared to the average snail
<Heee! Hence the term 'clings like a limpet'!>
..they seem to be good algae eaters. For some reason one of the adults does bother one Blastomussa wellsi that I have.
<Funny you should mention that. I had the same experience with one of the limpets I had. I caught it munching on my favorite B. wellsi one morning and promptly banished it to the fuge!>
It almost destroyed it 3 times already but each time it recovered.
<That's the great thing about Blastomussa wellsi, in good conditions even a polyp that's been reduced to a near speck can regenerate itself.>
I now keep the Blasto on my crushed coral figuring the limpet will not like to pass over that and since then it has not harmed it.
<Good thinking>
I also have a few Strombus snails, the kind that lay these little round see thru packets of eggs.
<Are they the snails typically referred to as 'Strombus Grazers'? If so, they're more than likely Columbellids, aka 'Dove Snails'. They're wonderful little grazers that reproduce like rabbits. Please see the following link for more information and photos for comparison: http://bb.wetwebmedia.com/viewtopic.php?f=25&t=341 >
I used to have 6 adults but now have 2 plus 3 small ones. I still see many egg packets but it seems that very few make it.
<Something may be preying on them or perhaps there's just not enough food to go around.>
These things seem to go in cycles. I used to have hundreds of Stomatella snails and now am down to a few here and there.
<Don't you just love these little snails? Sadly, other critters love to pick at, and eat them, particularly peppermint shrimps.>
Just sharing,
<Thank you for your terrific observations!>
<Take care, Lynn Z> 

Stomatella Spawning Constantly in Nano! Help! 4/9/10
<Hello Megan, Lynn here today!>
I have come across very little negative info about Stomatella...the closest thing I saw to a caveat was on WWM...someone with a larger tank than mine was assured that Stomatella spawn (unlike coral or clam spawn) is pretty harmless in a larger tank (I think the guy had a 75 gallon) and that this is not normally a problem, "except maybe in a Nano..."...but the crew member did not elaborate...
<Yep, usually they're a welcome addition and not a problem.>
Well, I have a Nano....12gal.
<Uh-oh, NASA we have a problem.>
We started with one tiny Stomatella from the LR, then did not understand why our water was cloudy for a few weeks.
<That's an awful long time to stay cloudy. Did you try checking your parameters and running carbon?>
Then we saw new snails. Now, we have seen them spawning with our own eyes, and so realize why water had tiny particles, back then & now.
Back then we only had the one adult snail, water cleared up fast.
But now we have 10-15 adults and they have been spawning every single day for past 3 weeks!
Doing water changes actually triggers spawning even more!
I do like these snails but wonder if this is good for my tank...the fish eat the eggs, but the Crocea clam I have produces a lot of mucus to get the eggs off of him.
<I bet. If the clam's getting irritated, then it's not good.>
The water quality is still good...nitrate has not gone up excessively, no ammonia, etc.
We have persisted with weekly water changes anyways because I don't want to have a dirty AND eggy tank.
<No kidding>
I realize we don't know what makes them spawn...so I just need to know if this is bad and what we can do to control the snails (if not their spawning).
<I would control their numbers. Remove and perhaps sell or give some/most away to fellow hobbyists (try a local fish club).>
I have very peaceful fish that do not eat snails and am not too interested to get a hunter type of fish but will consider any advice!!
<That would be my next recommendation, but only if you want to get rid of them all. Peppermint shrimp (Lysmata wurdemanni) reportedly prey on Stomatella snails, along with some crabs and hermits. Unfortunately, all of those can be pickers of other things as well and cause problems. Personally, I would opt for reducing the population and running carbon or something like Pura Filtration pads to help clear the water.>
Thank you as always for help with this extremely specific question.
<You're very welcome and good luck!>
<Take care, LynnZ>

Re: Stomatella Spawning Constantly in Nano! Help! 4/12/10
<Hi Megan>
Thanks so much for the detailed reply!
<You're very welcome!>
We had a peppermint before. He kept the Aiptasia under control (ate them any time they started to grow)
..but I hated his picking
<Yep, that can really be annoying.>
...and anyways he died, natural causes I think (he molted 3 times in one month and the last time he died). We did get another small peppermint last week because the Aiptasia have slowly started to come back
<Aiptasia can multiply quickly in systems with excess nutrients, so do try to keep them as low as possible. Hopefully, reducing the Stomatella numbers will help with this. Please see the following links for more information regarding:
Nutrient control: http://www.wetwebmedia.com/nutrientcontrol.htm
Aiptasia control: http://www.wetwebmedia.com/marine/inverts/cnidaria/anthozoa/aiptasia/aiptasia.htm >
...did not know he would eat snails also
<Oh yes. Stomatellids, since they can't retract all the way under their shell, are vulnerable to a lot of critters. In a tank without predators, you'll often see them out and about during the day; otherwise, they're mostly nocturnal. The problem is that Pep's seem to do most of their picking and eating at night so the poor Stomatellids never get a break.>
...but he picks too, and is picking at my little colony of brittle stars
...and so his days may be numbered in our little reef.
<I don't blame you.>
We changed the carbon bag to polish up the water and Stomatella seemed to have stopped for a few days at least. I agree that manual removal is probably best idea...once we get over the yuck factor.
<I'd use something like an algae scraper to remove them from the glass and catch them with a net or turkey baster. If the snails are on the rockwork, you might just try nudging then suctioning off with a turkey baster.>
They are very soft, and the shell is like paper...plus they move really fast!
<Heeee! Yes, it's surprising how quickly those little guys can move, considering they're snails! They'll also drop the hind portion of their foot, just like a lizard drops part of its tail, when threatened by a predator. The detached section squiggles and squirms, hopefully distracting the enemy long enough to allow the snail to make a quick getaway. I just thought you should know about this in case it happens during collection. The snail isn't actually dividing into two, it's just trying to get away!>
Thanks as always WWM.
<It was my pleasure, Megan.>
This is a wonderful service to amateur reefkeepers everywhere.
<Thank you! Bob has indeed compiled quite a stockpile of information, hasn't he!>
<Take care, Lynn Z>

Tech - I from Kent Marine, and limpets 5/22/04 Good morning to all, <and to you in kind> Just a few questions for you, hopefully you can help. You usually have all the answers. I am curious if tech-I iodine supplement from Kent is okay to use. The label says it has free iodine. My test kit says it is a bad thing. <somewhat subjective here. There seems to be two "camps" regarding advocacy of Lugol's strong iodine solution (the nutritive iodine of color/odor) versus clear Potassium Iodide solutions.  The other troubling thing is several keyhole limpets in my hospital tank. I believe both can be useful, both can indeed be abused/overdosed too. I favor Lugol's based solutions FWIW. I'm not a bog fan of some bottled supplements though... then ones that do not date their products for products with a definable lifespan/shelf-life. Iodine loses efficacy over time once mixed ion solution> scoured WWM and have found two different opinions. Bob says okay and Anthony says they will eat soft coral flesh. I did find a big one sitting on my flower leather, so I pulled him off. <some Limpet species are algae grazers, and some are predators on various reef invertebrates including corals (these tend to be the colorful ones with frilly/fleshy mantles). It depends on the species.) Thank you for always being there for me and my tanks. Thanks, Hopeless reef keeper- Daniel <best of luck, Anthony>

Stomatellid Snail... a Good Guy - 9/20/03 I have your latest invert. book and I found the creature I'm looking for which came with some live rock I bought but it doesn't mention whether it is harmful to soft corals or other reef creatures <hmmm... do check again, my friend: page 202 photo caption (underfoot pic) of Stomatella... "a harmless, nocturnal herbivore to be shared among aquarists." They are very strict herbivores in fact and are completely safe with corals> also I have a crab about the size of a quarter that is a grayish black large front claws and a rough texture doesn't like light in fact they seem quite common in live rock I had them before (good or bad) <most crabs are risky as opportunistic omnivores... I rarely recommend crabs for reef aquaria. I suggest you remove it to another aquarium. Kindly, Anthony>

Removing Limpets Hello! How are you? <Not too bad this morning.> I have quite a few keyhole limpets in my tank, and I would like to send some of them to another member of our seahorse group. There were a lot of limpets on the glass of my tank a few days ago, so I thought it would be easy just to swoop them out with a net. Wrong! Every time I even touched them with the net they would lock down with incredible force. I read somewhere that they can lock down with 70 lbs of pressure. Do you have any suggestions on how I could get a few of them out so that I can honor my promise to send some to my co-hobbyists? <If you grab hold of them and twist, you should be able to free up a couple. Removing from the glass is best. It would be very hard to remove them from the rocks without damaging them.> Thanks, Kevin <You are welcome. -Steven Pro>

Limpet Attacking a Flame Scallop? Last night I saw a Limpet attached to the bottom of my Flame Scallop and I didn't think anything of it until I looked at my Scallop this afternoon and when I tried to get the Limpet off of my Flame Scallop he felt like he was locked on my Scallop, and I had to actually pry him off. <Yes, it is very difficult to remove a Limpet from any surface. They have an incredible suction power.> My Scallop looks like he was dying. <Agreed> He is shrinking up on the inside and I don't know what is wrong with him. <Please perform a search of Flame Scallops on www.WetWebMedia.com for the reasons.> He is not responding to touch like he used to, his shell does not close right away when he is touched, and when you try to close him it feels like he is almost locked in the open position. I did some research on Limpet's this evening and I didn't like what I read on some of them. <Perhaps do some research on Flame Scallops. I am positive you will not like what you find about them.> Is it possible the Limpet was boring a hole in him and getting ready to eat him? <Nope, your scallop is and has been starving to death.> My scallop was fine for months until now. <No, you just did not notice its duress.> Please give me your suggestions on what could have happened to him <It is starving just like almost all do.> and what his chances of survival are. <Next to none.> Thank you for you great expertise! Connie <Please research your animals and their care prior to all purchases. -Steven Pro>

Limpets A year ago I noticed two limpets in my aquarium. It is a 90 gallon (6'x1'x2'). My guess is they came in on the live rock I added 7 months before. The curious thing is this. It took 7 months to see the first 2, and I now have roughly 100 more. They are black with a white stripe on their back and are actually not unattractive despite their numbers. They do a good job keeping the glass, and everything else, clean. They range in size from 1/4 inch to 1 1/2 inch and are found everywhere from the skimmer collection cup (always a few small ones on the cup of a CPR Bak-Pak), to the live rock, to the glass. I have about 80 pounds of Fiji live rock, a 1 inch aragonite sand bed, the CPR, and a couple Hagen 802's for circulation. I also have Naso, yellow, and regal tangs (1 of each--all about 3.5 inches), a coral banded shrimp, a false percula clown, and about a dozen snails and small hermits. There are no corals or anemones. Ammonia and nitrites are 0. Nitrates are close to 50. S.G. is 1.024. Temp. is 76 and pH is 8.0. I add no chemicals and have 0 algae other than coralline which covers most everything and has to be scraped from my glass at least every two weeks. I have two questions. First, is this an extremely unusual occurrence? In order to identify these things I had to post pictures to a newsgroup since the few inexpensive books I have don't even mention them. Second, I'll be adding a dwarf lionfish and snowflake moray to the system tomorrow. Will either/both decide to make a feast out of the limpets? If they do, it would probably be good for them, since, in their numbers, I think the limpets would be able to sustain enough of a population to meet their dietary requirements. By the way, when I first set up this system roughly two years ago, I dosed Kalkwasser for about 2 months to try and get the coralline to grow, and it didn't. Ever since, I have added no chemicals (other than synthetic salt and frozen food for the fish) to the aquarium, and the coralline is almost out of control. It's a great problem to have. By the way, I have 6 24" fluorescent bulbs. Four were bought at home depot (cheap bulbs), while the other 2 are actinic. I also have a large population of feather dusters growing out of the rock and some have even built tubes of up to 2 inches and are living in the sand bed. Is this extraordinary luck, or did I accidentally hit on the aquarium conditions that the worms, coralline, and limpets thrive in (i.e., low light and not-so-low nitrate)? If my experience is unusual, I'll probably try to replicate the environment (minus the fish) in a 29 gallon, devote some study to all three, and write a paper detailing the conditions for anyone that might want to duplicate them (though their suitability would be limited to a fish only situation). Any guidance would be appreciated. Thank you in advance for your time. Sincerely, Richard Weatherly >> Wow, what an outstanding query, relating of experience and uplifting story... Congrats to you. And I think you may be on the verge of a great commercial success. I have only seen a few cases where the snails called limpets were so abundant as yours... and they are a blessing... And your lion and eel will not consume them (different diets all the way around), but I would do as you say, and save some of these "Chinese Hats" in another system... if for no other reason, for just safekeeping. And do "share the wealth" and supply some to fellow hobbyists... Your relating of the non-supplement use and results is exemplary by the several meanings of the term... Thank you for writing... please do consider tallying up your observations and sending them to one of the hobby magazines... Very useful. Bob Fenner

Gastropods/Snails/Limpets and an Over Abundance  12/5/05 I'll save space and your having to read by not listing our tank setup - if you need to know the setup to answer this question, let me know and I'll oblige. <Okay.> We setup 90 gal tank with 130 pounds Fiji and Marshal island live rock about 5 months ago. Within a week, we found a large cap snail hitchhiker...5 months later, there's so many in the tank (also a few in the refugium) we lose count to get an exact number. I've read if you know how many snails you have, you don't have enough, <This sounds like a retailers slogan 'I to have heard such ludicrous rules of thumbs such as this one and the common 'One hermit and snail per gallon rule' which is to say the least ridiculous.> but is there such a thing as TOO MANY CAP SNAILS? <If you have an overabundance this means that there is sufficient algae to support them. The algae is fueled by nutrients. So if you want the herd to be naturally thinned out I would check your system for detritus build-ups and watch how much you feed. Water changes are your friend.> If so, is there a natural predator for them? <Yes likely any mollusk and crustacean predators such as wrasses and puffers. However they will not limit their predation to just your snails, your microfauna population would be adversely affected as well as any other small critters in your tank.> cheers <To you too.> Donna <Adam J.> 

Snails Everywhere! Hi everyone , I am a little concerned about crustaceans that are in my tank. I seem to have small , about a quarter inch, snails and also limpets in my tank , I have soft corals as well as mushrooms and polyps. Are these critters harmful to any of my other occupants . Thanks Rich <Well, Rich- without seeing them for myself, I can only generalize (gulp!)...Most of the commonly encountered snails and limpets are harmless...I'd keep an eye on population levels, and if you start noticing damage or excessive populations, you may need to remove some. The upcoming "Reef Invertebrates" by Bob, Anthony, and Steve Pro may be a big help in identifying these little guys. Take care! Regards, Scott F>

Limpets and Coralline Crew: Well after trying to figure out what I can't grow coralline algae in my tank, I think I have finally identified a suspect.  I have a few of those odd little creatures known as limpets (Elephant Snail, Keyhole, etc.) and according to an article by someone named "Steneck" http://academics.smcvt.edu/dfacey/AquaticBiology/Coastal%20Pages/Limpets.htm These things only eat coralline!!   It really makes sense now because I could see little patches of coralline one day, only to wake up the next morning to find them vanished!  All water parameters, Ca, dKH, etc. are all perfect - no phos, no nitrates, etc.  I guess I'll continue to let them battle it out (I refuse to attempt to remove one of the limpets for fear of damaging him) and see who wins - right now, it's no contest!  You agree that this is possible? <Definitely. These are voracious grazers.  Best, Chris>

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: