FAQs about Marine Snails 1 Related Articles: Gastropods, Mollusks,  Sea Slugs,  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, & Marine Snails 2,  Marine Snails 3, Marine Snails 4, Marine Snails 5, Snail Behavior, Snail Selection, Snail Compatibility, Snail Systems, Snail Feeding, Snail Disease, Snail Reproduction, Mollusks,  Sea Slugs,  Abalone,  Turbos for sale.

When is a Welk a Whelk? (Not Lawrence) - 10/24/05 What is a Welk <sp>? <It's "Whelk", mollusk/snail.>  I've heard that they look similar to Conchs and are from the Sea of Cortez, <Many different species of whelks that range all over the world, mostly in tropical waters though.> but since I cannot seem to figure out how to correctly spell the name, I can't find information on them. <Now that you have the name just Google WWM or just Google period. In short they are mostly carnivorous animals that can make interesting displays and good detritivores in fish only tanks but most aren't the best mixed reef citizens, Adam J.> 

Re: A mysterious end Hi gentlemen, <cheers> Thanks so much for your help with this. In fact, I did add about 12 Astrea snails to the tank over a week ago without quarantine. That's probably the answer.  <Ahhh... yes. There is a much higher incidence of parasitic disease with Atlantic livestock in aquaria (in this case carried in the water with the snails)>  Unfortunately I'm not sure how to go about quarantining snails.  <all things wet should be quarantined...live rock, plants, corals, snails, fishes, etc). In many cases (most) no medication is necessary... just a 4 week period where most pathogens will be expressed, die and/or wane without a viable host> What would they eat to stay alive in a quarantine tank?  <the same thing they in in the other glass aquarium (your display): diatoms off the glass, Nori seaweed from you... grazing on a small piece of live rock added. Think of QT as more of an observation period than anything.> My main tank has plenty of algae to munch but pickings are pretty slim in quarantine. <algae wafers, Spirulina tablets, etc. Many options here my friend> Thanks again, Andy <best regards, Anthony>

Re: Strange thing growing on clam shell I just sent the image earlier and I'm attaching it right now. Thanks. <no worries at all... your hitchhiker is a harmless Vermetid snail. They are sessile (non-moving) filter feeders... and you may notice that they secrete a mucus web which they issue to collect microorganisms before sucking the web back in for digestion. A fascinating creature. Enjoy. Anthony >

Fish eating Turbo snails Dear Mr. Fenner et. al., <Steven Pro here this evening.> How do you do? <Ok, but awfully hot here now.> I have a question regarding Turbo snails. Are they scavengers? <No, more algae/diatom eaters.> I was away for a 3-day vacation and noticed that my bicolor Pseudochromis went missing. I removed all my 25 lbs. of live rock, flushed it, ran my fingers throughout the substrate but still no Chromis. Could he have died and eventually consumed by the snails? <They are many other creatures in your tank that could have worked on consuming this small fish; copepods, amphipods, worms, etc.> I have 7 Turbos and 1 Astrea in my 20G. Thanks in advance. Best, Mimi Eliza <And you too! -Steven Pro>

Snail problems Good afternoon guys, I am having a problem keeping snails in my tank. First the stats; at last test yesterday, temp 80, salinity 1.024, ph 8.4, zero amm., nitrates and phosphates, calc at 400, Alk at 5.5meq/l. It is a 37 gallon with a Remora skimmer, CPR hang on refugium and about sixty pounds of live rock.  <all sounds very fine> I have only a Banggai cardinal in it right now. Last time I thought maybe I didn't acclimate them properly, so this time I took four hours adding a couple of tablespoons of water every ten minutes.  <wow... impressive!> They were active in the bag then when I put them in they go completely inactive leaving their foot outside the shell and not moving at all. Is there something I am not testing for that could be the cause?  <notorious magnesium sensitivity... what brand of salt do you use. I have heard many aquarists complain anecdotally for years about a certain company that has changed their name a couple of times. If not using a mainstream brand like Instant Ocean, do consider> I have purchased snails from a variety of sources to no avail. As far as supplements, I add two part calcium, essential elements and Iodine all from Kent. Any help would be greatly appreciated as I am growing more discouraged. As always thanks, Lowe <do consider a Poly Filter with consideration for the possibility of another metal contamination... indeed a common snail. starfish killer. Best regards, Anthony>

Snail Deaths Dear Mr. Fenner, <Steven Pro in this morning.> I have a problem that I can't figure out so I thought I'd consult your expert advice. My problem is that my turbo snails die within a month of introduction. Tank is a 75 gal. approx a year old. Overflow to a TF1000 in a 20 gal sump. 299 watts pc lighting ( 2 full/1 blue), 90 lbs of LR, 1 inch of arg. sand, 2 Rio powerheads for circulation. Temp: 78-79 Salinity: 1.023 PH: 8.4 Nitrite:0 Amon:0 Nitrate: 20ppm CA: 350 (trying to get it up w/Kent 2 part solution) ALK: 7meq/L <Calcium and alkalinity are a both a little low. It is going to be expensive to raise and maintain both using two-part solutions. You should investigate the use of calcium reactors and Kalkwasser on the www.WetWebMedia.com page. Not related to your problem with snails, however.> Copper: 0 Phosphate: ? (buying this weekend, but I assume low b/c I use RO water). Activated Carbon in sump. Weekly 8 gal water changes with aerated (24 hours) RO water (Not RO, DI) and Instant Ocean mix, heated to tank temp - but can't get the ph to same level as tank, only 8.1 - 8.2. <All sounds good.> Current tank inhabitants are 1 maroon clown, 1 blue damsel, 1 bar goby, 1 Banggai cardinal, and an oddly well behaved domino damsel that I cycled the tank with. All fish are doing great and even found a small colony of polyps (green centers with brown tentacles tipped green - I.D?) <Sounds like Zoanthus.> growing on the backside of a piece of LR. I acclimate the snails according to your book, and they seem to do really well the first few weeks. Then slowly, the snails fall off the rocks, and lay still upside down for days (I assume they're dead and not admiring the lights above). I started with 3 snails, then another 3 - all dead. I thought it was copper from some "unknown" source and had it tested for a second opinion at the LFS - not a trace of copper. I've never treated my main tank w/copper, but have it on reserve for my QT in case I need it. My second purchase of 3 snails came from a completely different store because I wanted to make sure they were healthy, if the original 3 were not. Same results. Other problems included green hair algae which has diminished with an adjustment to my skimmer (more flow), manually picking and siphoning, and reduced feeding. I plan to add some Caulerpa into tank soon. I don't think the snails are starving because I can see a "cleaned trail" on the LR as they graze. <Neither do I.> They just seem to suddenly slow down after 1 week, slow down after 2 weeks, and by the third or forth - they fall off and lay still (upside down). I've even banned smoking in the entire house 2 weeks ago because I thought the skimmer was sucking in 2nd hand smoke from the air and injecting it into my water (do you think they have a nicotine fix?). <No> I'd like to add more snails and maybe a cleaner shrimp, but want to figure out this problem before adding anything. I have a feeling that it has something to do with my water changes. <Not likely. Salinity shock is a concern, but does not seem to be your problem.> Any ideas? <Yes, actually a rather simple one. I am guessing you have Astrea species snails. This is what most "turbo" snails sold in the trade are. Astrea, for whatever reason, are incapable of righting themselves after falling off of the rock and landing on sand. They lay there for a while until they die. The next time you get some snails, try to find some "Turban" snails. They are larger and their shell spirals sideways versus the Astrea snails shell that rises up to form a cone.> Thank you for your time and apologize for the long email, but I wanted to give you the "full picture". <No apology necessary.> PS. I think I glanced somewhere that you have another book out. If so, what is the title? Need to add to the library. -Bob. <Bob has written "The Conscientious Marine Aquarist" and "A Fishwatcher's Guide to the Tropical Marine Aquarium Fishes". Bob, Anthony, and I are currently working on another book with a working title of "The Best Reef Fishes for the Modern Marine Aquarium." -Steven Pro>

Astrea snails and coralline algae Greeting and Salutations Bob or Anthony, <I'll take the salutation, and raise you a "Whassup?", Anthony> Quick question for the experts: I just added some nice cured LR to my system with some beautiful purple coralline algae growth. This morning I noticed one of my Astrea snails "sitting" on top of the coralline on the rock. Will these little guys eat the good (translate: pretty) algae or will they restrict themselves to the green stuff?  <they will only eat microalgae and they favor diatoms (brown algae)> Thanks so much for all the time and quality you guys put into WWM. I hope you're raking in crazy loot with the advertisers otherwise I'm sure there would be many willing to pay a small subscription fee! <actually the wine, roman parties and dancing girls nightly are payment enough> PS-Anthony--didn't realize you were from the 'burgh, me too! Any recs. as to places for good quality live stock/LR around here? take care my friend. <Adam...too cool. Yes, reasonably good stores... what part of the city are you from? Perhaps your best networking might be through our local marine society. We take frequent road trips (subsidized by the club) to the best regional stores within a 6 hr drive! We also have great speakers like Bob Fenner and Eric Borneman annually just to name a few. Do look us up at www.pmas.org or contact me if you'd like more info. I hope to meet you someday, bud. Kindly, Anthony>

HELP???? Jelly naming, color seashells by the seashore Hi Bob!! <Hello Drew> Can you help with 2 questions for my class? <I will try> 1) Why are Jelly Fish called fish? <A "generic" term that folks used to apply to most any/all animals in the sea. Even marine mammals like dolphins used to be called, considered "fish"... and eaten on "non-meat" days by Catholics!> 2) Why are shells in tropical areas so much more colorful and fancy? <Some investigators speculate that many bright colors, patterns are "warnings" or false warnings for would-be predators to steer clear... lest they be envenom zed, poisoned... Other times these and odd-body shapes may serve as disruptive camouflage to hide these animals... perhaps at times to attract mates, identify them as members of the same species.> Thank you so much! Drew Morgan <You are welcome. Bob Fenner>

Question about limpets HI Robert, I found your article on Mollusks: An overview on the internet and decided you would know the answer to my questions. We watched two limpets in a display last night in our tank that we think might have been their reproduction process but we are unsure. Both key hole limpets were on the glass, the smaller one ( 1 1/4 in long) was releasing from the key hole an almost clear liquid that would disperse into the tank. It looked almost like smoke. The other, larger one ( 1.5 in long) was higher up on the glass and the release from this limpet was whiter, thicker and dispersed slower. They did this back and forth for at least 30 minutes that we were aware of. Were we watching the release of eggs and sperm? <Likely so> If so, how long will it be before we will see tiny limpets in the tanks? Is this common? If not, what were we watching? <... probably won't see limpet young... the products here will probably be collected by your filtration... removed by skimming... pelagic larval stages have tough times in captive systems. Bob Fenner> Please email your answers to XXXX. Thanks! Carol Griffith

Snail Population Bob, and/or Crew I have enjoyed both this site and the book CMA. It has made the setup and maintenance of our 55g salt water reef tank enjoyable. I have two questions for you. First, I have a plethora of small snails in my salt water tank. The snails are pearl color and some of the shells are white with brown stripes (kind of reminds me of a zebra). I would not mind them, in fact I would have thought of them beneficial except there are so many of them throughout the tank. When I turn off the light in the tank they really come out in full force. The snails look like the turbo snails that I currently have. What are these snails? <Can't tell definitively by your description> And with there so many how do I get rid of some of them. <A wrasse species would be my first choice here... of a type that will get along with your other livestock, system> Currently in the tank is 1-coral banded shrimp, 1-cleaner shrimp, royal , Gramma, ocellaris clown, 3-scissor tails and a variety of hermit crabs. I also have some button polyps, White clove polyp, colt coral, and a Derasa Clam currently in the tank. Is there something I could add to help with population control of the snails (fish, or invertebrates)? <Perhaps a Cirrhilabrus, Paracheilinus species... these are detailed on WetWebMedia.com> My second question is my LFS has some Signal gobies (Signigobius biocellatus). I was wondering how hard are these little guys to keep and ultimately to feed? They have two but they are not a mated pair. Should I get two or just try one? <Should only be kept in pairs or more in a large-enough system... Not a really hardy species... easily lost by the less than diligent> Thanks for all your help that you guys have done in upkeeping a great site full of information. I realize I still have a lot to learn. Thanks again. Sean H. <We all do my friend. Bob Fenner>

Possible I.D.? I found this 1.5 inch creature in my FOWLR tank. The tank is approximately eight months old, however, I did add some new live rock approximately two months ago. The picture is rough, but the object in question is a plum colored soft bodied animal. Any ideas? I looked through the material on your site, Nudibranchs and flatworms, but found nothing exact. Any dangers? <Mmm, bizarre... sort of like those old UFO pix. Maybe a type of Opisthobranch snail... I would remove it. Bob Fenner> -ed

Marine Snail Reproduction This morning I noticed about 8 tiny snails (head of a pin size) around one of the front corners of my 300 gallon reef tank. I have 12 adult Astrea snails in the tank, added about three months ago. I assume that somehow they are breeding ? <although Astraea snails have been regularly observed spawning in captivity, it is rare if at all possible for it to be successful in the confines of aquaria> Due to the proximity to an adult, it seems to me that maybe they were "born". Can you give me some info on the reproduction of this type of snail. Many thanks ! Steven C. Youngblood Houston, TX. <Steve, more than a few species of snail imported with rock and sand commonly reproduce asexually in aquaria. Most likely, what you have is a non-Astraea species. Describe them as they get larger and we'll get a scientific name for you. kind regards, Anthony>

Aquarium question (marine snail behavior) Hi, thank you for your time. I was just wondering why my snails seem to spend all their time at the top of the tank. Is this normal or is this some indication of poor water quality? <Could be part of a given species, populations natural behavior (many are amphibious) or could be "water quality" as in low oxygen... even "low food"... or even just adventitious behavior... a quality of living things.> They are turbo snails in a new (2 months old) 45 gallon reef tank. Thanks. <Oh... maybe lack of oxygen, food, water quality. Bob Fenner>

WTB: Good Hello... not much time to write, three week old baby demands all of my time! So, to be brief, just two nights ago I lost a Naso tang. Found her in the morning. :( Can't figure the cause, either- she was swimming and eating like usual when I went to sleep. Anyway, today I saw the most disgusting thing on my tank glass. It took me a few minutes to realize it was a snail... with no shell. No, I don't mean one of those critters that aren't SUPPOSED to have shells. This is one of my old snails, just one of three. And he used to have a shell, I assure you. <Hmm> My first thought was to get rid of it- it must be dying. But, it seems to be fine. Well, not FINE, but okay. He's moving and eating. So then I thought, move it to the refugium so none of the fish eat him. But... if he dies down there, I'd never know it and he'll just pollute the water. <Maybe...> Taking longer than I thought... okay- any thoughts on my suddenly shell-less snail? <I wouldn't be overly concerned if the snail is "small", the system "large". Not that much chance of pollution... This maybe a new snail/Opisthobranch, not one of your old ones sans shell... still no problem. Bob Fenner> ~John

What eats acrylic? Dear Bob, A quick thank you for all you've done for us "salts" out there. I reference WWM frequently and often and thank you and Lorenzo for all the time, effort, and sage advice you've devoted to people's better understanding of the life forms and biotopes they keep. <A pleasure and honor my friend> I have a question regarding what I believe to be radula marks etched into the surface of an acrylic tank. I recently helped a friend break down his 40 gal. tank (SeaClear or TruVu, I'm not sure which). He had (sadly) neglected any maintenance on the system since his last specimen died some two years ago, only adding top off water. Needless to say it was a huge mess, but somewhat of an interesting study from a scientific perspective. As I began to scrape of the thick filamentous algae covering all sides of the tank, I noticed a haze on the front panel. Upon closer inspection, this haze was a pattern of etchings in the acrylic surface! The pattern matches that which I have seen snails (esp. turbo) leave as they graze through a patch of Cyano. Is it possible for snail's radulas to be so hard as to etch into the acrylic?  <Yes... for browsers, many gastropod mollusks have a rasping mechanism... a "tongue" called a radula (important in its characteristic make up for species identifications at times) that is constantly being regenerated in the back of the mouth, worked by a muscular device, the odontophore... that these various "snails" use to scrape away micro/macro algae et al. from hard surfaces as food... Some have modifications, additions of specialized salivas, bore into shells, melt rock...> I am wondering if you have ever encountered this, and if so, what species of snails you have associated it with. I am sure this info would be quite interesting to everyone out there with an acrylic reef tank. <I have seen this sort of marking... and simple "stress fracturing" that looks similar... in acrylic tanks. Don't know which specific species might be involved though. Bob Fenner> Sincere Thanks, Karl

Blue-Green Algae and Snail Deaths I have read through your site and found a lot of helpful information. I have also looked through FFExpress for info but my problem is still persistent. I have tried large 20% water changes, I even tried 50% once and killed a starfish. I use R/O water a 24GPD Kent Marine TFC to fill the tank, for top off, and water changes. Let me describe my tank: 90 Gallon 10 Gallon Sump rated for a 125, Balls removed CAP 2200 Return Pump 50 Pounds Rubble Manano Rock 50 Pounds Fiji Walt Smith 50 Pounds Mixed Course/Fine Atlantic Crushed Shell Aqua-C In Sump Skimmer Rio 1700 for Skimmer Rio 1100 In Tank for Movement 2 Air Stones for movement 6 4' Fluorescent Tubes 2 Actinic, 1 50/50, 3 20,000 Lux - 13 Hour Timer 0 Ammonia, 0 Nitrite, 0 Nitrate, 0.5 or less Phosphate, <I'd shoot for zero percent...> 350+ Calcium, 8.4 Ph 78 degrees F The tank has been up for 5 months Kalkwasser,  <Drop the Kalkwasser habit, and get on to using two part supplements here> Strontium, Iodine added every 3 days 1 Yellow Tang, 1 Huma Huma, 1 Green Chromis, 1 Striped Damsel, 2 False Percula 2 Green Brittle Star, 1 Chocolate Chip Star, 1 Cleaner Shrimp, 4 Green or Mithrax Crabs, 3 Snails down from 12 I know I need additional movement and I am going to add 1-3 move Rio powerheads 1100-2500? My big question is when I do a weekly water change I remove 80%+ of the algae with gravel backing but a day or so later it is back and still as unattractive as before. I have been hoping the tank would grow out of this ugly stage soon as my other previous tank had but it only had a diatom problem due to my overfeeding.( Porcupine Puffers are so cute and always hungry, I could not resist) The Holidays are fast approaching and I have the honor ( or at least the largest house ) of hosting Thanksgiving. I would like to solve this problem by then. <You need to undertake a few approaches here, maybe chemical filtrants, in addition to enhanced circulation, competition by macro-algae...> As a backup plan I was going to do a water change that morning. This tank is my pride and joy and I want it to look as good as I know it can. After a water change when the tank settles it is truly a live piece of art. I care nearly as deeply for my pets as do I care for my family. Please offer any advice you can.  <My advice on algae control is posted on our site, www.WetWebMedia.com, have you read the sections on it there?> I also have been losing Turbo Snails, I suspect the Chocolate Star. I have watched him crawl over an overturned snail before it can right itself and sit there for hours, not moving. The trigger has also picked at the lest than healthy ones. If you can offer any advice I would greatly appreciate it. <Read my friend. Bob Fenner> Sincerely, Joseph M Howell

Dying snails Hello Bob, I wrote to you not so long ago. You were a great help to me! I wonder if you could help me again. Two days ago I was inspired by a post I read on your daily Q&A and decided to rearrange my LR. I did so and it looks wonderful. I changed the water yesterday and though my corals showed some stress they are back to their original glory. <Ah good> My problem is that I have found three snails dead today. I checked my water Ammonia & Nitrite 0, Nitrate 5ppm, Alk 2.8milq, Ca 425, those are my normal tests. My skimmer is bringing out more then normal but I thought that was because of the mess I made. <Yes... and the transient chemical changes likely the cause/demise of the snails> Do you have an idea of how I can find out why my snails are dying? I pulled them out as quickly as I could. Would it be a good idea for now to run some activated carbon?  <Yes, a good idea> I'm not sure what else to do. I though maybe because I rearranged the LR added some dead rock (cycled & cleaned well) 10lbs, and 20lbs of new LS I messed up the food chain. Thank you for your time! Libby <Not likely a long term challenge. Your system is likely re-stabilized now, but I would run the carbon. Be chatting. Bob Fenner>

Cowries Bob, I have kept a cowry in a 10 gallon tank for 4 months, along with live rock and a Domino damsel, and I recently purchased a 55 gallon tank and is currently in the process of cycling. To accelerate the process I have added my live sand from the old tank to the new, and added the domino damsel as well as a velvet damsel. Both seem to be doing fine, however when I moved the cowry (Cypraea mauritiana) to the new tank, she has stayed retracted in her shell. This morning I moved her back in the old 10 gallon tank, waiting to see if she will move at all well that usually takes place at night). I have tested the water in the new tank and it was PH 8.2, Nitrite 0, Ammonia 0.25-0.50, Nitrates 0ppm(I think,...I'm new to this). <Mmm, the Cypraeids are sensitive to "new tank" conditions... the ammonia was likely harsh here... and a good idea to not lift these mollusks into the air (better to move on their rock in a bag, plastic jar...> Do you think I should have waited longer to introduce the cowry to the new tank? <Yes my friend> She usually feeds on algae (scraping rocks or the glass). Also, I haven't been able to find any info on cowries. Would you suggest a particular web page? Please advise.. Thank you, D. <Please insert the name of the family "Cypraeidae" into your search engines. Not much of "practical husbandry" on these shellfish on the net... but some. Perhaps you will write a definitive piece on their captive care. Bob Fenner>

Snails Hey Bob, Lately I have noticed several little snails in my tank, about 30 to 50, maybe more that I haven't seen yet. Are they safe? Should I get rid of them? <Time for you to get a couple of good reference works my friend, and read through them. Who can tell from your description what these snails are? Or if they're deleterious? I would leave them be... Bob Fenner> Thanks Jason P.S. The Rena canister filter is working great in the tank, I also added a Rio 600 powerhead with dual wave arms.

Re: snails Bob, Hey I know I need some good books, what do you recommend? Title/Author? Thanks Jason <Please read through the reviews posted on our site (WWM). Bob Fenner>

Small spiral worms? Bob, You are so awesome. I have been trying to get various people to answer me on the filter questions for about a month, and you answered in one day. <Hmm, why not?> Thanks you, thank you, thank you. I have one more question. When I came home today I noticed a small (1/4") transparent flat worm with a forked tail on my glass. I was reading on your worm section and noticed that the flat worm that is related to the black spot disease with Tangs are related. I recently had a tang die in my tank. He had these black spots and I did freshwater dips, the black spots would leave, but I woke up one morning to see both of his sides eaten away. Needless to say, he did not survive. Is this worm responsible for this?  <Doubtful... but perhaps... more likely the Tang died from whatever cause and the sides were being eaten away by opportunistic organisms> I also very recently began to see small white spirals on the glass and shells in my tank. Are they related? Do I need to get rid of the white spirals? <Likely either encrusting snails or Polychaete worms of some sort... not a problem... just scrape them from the viewing panels... they too shall pass> I can not seem to find any info on what this might be. <Read through the marine invertebrate sections on our site: www.WetWebMedia.com and ask your queries of the excellent folks on our Chatforum: http://talk.wetwebfotos.com/> Again, thanks for the answer to my previous question. I know that I will only have success in the future with my tank, with you on my side. Julie <Looking forward to it. Bob Fenner>

Mystery critter Hey Bob , do you know what this is ? thanks ,Robert McNinch <Nice pix. This looks to me to be a Cowry, family Cypraeidae of some sort. Time to scan the Net. Bob Fenner>

Crab Control Bob, I discovered a crab in my 75g reef tank a couple of months ago which I assumed to have been a hitchhiker on my live rock. I didn't give it much thought at the time but I did some reading which indicated that some types of crabs can be detrimental to the tank including corals, hermit crabs, small fish, and snails. Well - this weekend I saw him again for the first time in about a month and he is now about the width of a quarter, light brown (almost beige) color, and has a hairy appearance. I noticed that he has taken refuge on the bottom of the tank under a large piece of live rock. I monitored him for while and much to my chagrin observed him sneaking out from his refuge and capturing small Nassarius snails which he then transports back to his hideaway and assume he then consumes their meat if he can. Given the obvious difficulty in trying to capture this nuisance - I'm writing you to ask for any insight you may have in trapping and removing this crab short of removing all my live rock to find him. Your thoughts would be appreciated.. <Bait, trap this crab out and remove it. Some instructions on how to do this under "Crabs" on the WWM site. Bob Fenner> Thanks, Rocky Phillips

Die-off dear bob, I wrote you several weeks ago re: snails going "dormant" when introduced to the tank. then they die of starvation. In addition, my coral, one at a time, are dying. all my water test numbers are good. you suggested adding magnesium. this has not worked. could it be possible that a bacterium has invaded the tank and is causing the damage?  <Very unlikely... much more common are chemical, physical anomalies... please do read through the "Toxic Tank FAQs" part of the Marine Index on our site: www.WetWebMedia.com for accounts of others> I also have a large growth of hair algae growing on live rock and decorative (non-live) coral. any suggestions, I am almost ready to dismantle tank and give up ( after 10 years). awaiting your response to help me. <Perhaps the best idea is to tear down the system and re-set it up... with new substrate, at least some new live rock... this is what I would do. Bob Fenner, who apologizes for late replies... am visiting in Asia.> thank you, Lowell Halpern

Milky Way of Snails!!! Bob, <Lorenzo here standing in for Bob-in-Asia.> I have a 125 reef that is really doing well, been up since September of 2000 and everything is really thriving. <Sure sounds like it!> I added 25 Margarita snails in September of 2000 and another 25 in December. Noticed the other evening with the lights off that their are literally 100s and I mean 100s!!!!! of little snails all over the place. They only come out at night and are shaped like the Margarita but their coloring (on the ones that are big enough to see) is similar to a Nautilus. <Yikes, wowsers, etc!> Anything to be worried about here? <You don't have any fish that would eat the planktonic stages of the snails? I'm kind of surprised you'd get so many. If you don't have a predator, most population explosions like this will work themselves out, when they grossly imbalance and exhaust the natural resources available in a closed system. The problem then is all the die-off. Your skimmer will go crazy, and you'll need to do frequent water changes to counter-act the over-driven nitrogen cycle. I'd say, get a predator to balance that whole system out. A small wrasse, like a Coris or Six-line might be nice, and probably effective. Banggai cardinals seem to eat anything that floats by as well, though the wrasses will eat most tiny snails, shell and all. -Lorenzo>

SNAILS Bob, I recently noticed a proliferation of baby snails in my 300g tank. It is a tank that I filled with about 200lbs of homemade "Aragocrete" (aragonite gravel/Portland white cement) that I recently (2months ago) added approx 80lbs of LR. The original clean-up crew (100 Astrea snails, {I think} & 100 hermits) were added about 6 months ago. The strange thing is the new snails have a completely different shell than the cleanup ones have. Is it possible that the new snails came in on the rock, or do you think my existing snails reproduced, and switched shells mid-life? <Do like the way you put this... but, no, these new snails likely came/are another species from the new LR> I thought snail larvae were planktonic, and thus would be chewed up by my pumps.  <Hmm, no, not all... some are "livebearers", others have demersal eggs with more or less direct development...> I have witnessed the snails squirting what I presume to be eggs and sperm into the water, but I am amazed that reproduction took place here. <Don't be too amazed... when conditions are good or bad... reproduction is a high priority> There are hundreds of the little guys. (I counted 120+ on the glass just now) Should I be concerned? Should I try to control the population?  <No to being overly concerned... There will likely be "checks" coming along... predators, competitors, a change in the availability of foods, minerals, that will limit this animals population. In the meanwhile no problems.> Thanks once again for your help & info provided. "Be chatting my friend." <Indeed! Bob Fenner>

Snails and hermit crabs Hello, I have a couple of questions about bottom feeders.... Do I need to quarantine snails and hermit crabs when I get them?  <Only if you suspect they may die easily, polluting your main/display system... if there are DOA's, the water smells badly... I would> How about dips, do they need that too? (I have read your book from cover to cover so I know about quarantine and dips :-) <I don't generally dip/bath snails or hermits> Also, I was wondering if cleaner shrimp and crabs get along alright (I'm thinking your book says "NO")? <Most species, most cases, no... many crabs will consume the Cleaner Shrimp, particularly at molting time> Thanks, Jana p.s. I am putting together my own, homemade protein skimmer right now and I tell you what - even if the dang thang don't work, I sure had fun doing it ! Everyone should make their own simply for the self-satisfaction. <I agree with your go-getter spirit. Good for you. Bob Fenner>

Snails Hi Bob, I love your website and find it very useful.  <Ah, good> I keep a 110g saltwater tank that has a variety of fish, a lot of live rock and some crustaceans, anemones, etc. My question is that about two years ago I purchased two "turbo snails" that have grown a lot and recently they have been doing something strange. They perch high up on a rock, lean way back and simultaneously discharge what looks like smoke from a tube that comes out of their body. It clouds up the tank a little and then goes away. I'm wondering what it is and if its poisonous or not. It's happened about four times now . Hoping you could help......Thank you in advance. Dave from New York <This does sound like a reproductive activity. And no problem given good filtration, aeration, circulation... Bob Fenner>

Species id Dear Mr. Fenner: I have a very curious tank inhabitant that I cannot seem to identify- maybe you could help. It is a gastropod-like creature that appears to be embedded in a rock. As such, it is stationary. In order to eat, it secretes a web-like material that extends for 8-10 inches and is very sticky (it has even hung up a little mandarin fish for a few seconds). After secreting the web for a period of time, the organism then re-draws the web back through its mouth, consuming the web and along with its contents. It is very interesting, but I have no idea what this animal is. Do you have any ideas? Thank you Samantha <Hmm, good description... and there are a few "commonly encountered" sessile invertebrate groups with feeders as you describe. Likely in this case a Sedentariate Polychaete worm of some sort (often called "Spaghetti Worms" in the aquarium interest... though could be many other organisms. Have an image of this on the "Worms" pages of the www.WetWebMedia.com site on the Marine Index. Bob Fenner>

Re: species id Hello: Thanks for the reply and info. However, I am fairly certain that my unknown creature is not a worm. It has a long snout (I'm not certain of the correct anatomical term for this feature) with a structure similar to a radula on the end of it.  <And an odontophore to "power" it? Maybe a mollusk of some sort then... but there are "worms" of this general description as well... If your LFS has a copy of the newest (3d) English ed. of "The Modern Coral Reef Aquarium) by Fossa and Nilsen... take a look at the diversity of Vermes offered there...> Also, it has a hard covering (again I'm at a loss for the anatomical designation) that can be closed/retracted in order to protect its mantle. Overall, it really just resembles a snail stuck in a rock. <It could well be... there are tubiculous snails... some are net-filter feeders...> For future reference, I'll try to send a photo of my unknown guest (I just got a new macro lens for my camera). I will also try to study up on mollusk anatomy in order to make an adequate description of the creature easier. (As an aside, I once had to memorize the 6 mouth parts of a grasshopper. You'd think that they would teach something useful, like snail body parts, instead. Oh well.) <I spent many nights memorizing HAM's attributes (Hypothetical Ancestral Mollusk) for LOL... for various marine invertebrate zoology courses... and still have at least four editions of Robert and no more Betty Barnes (and the myomeres from toting them about) to show for my pains...> Thanks for your interest. Sam <Chat with you soon. Bob Fenner>

Snails My snails were excreting what looked like a milky liquid tonight--lots of them were doing it. Is this reproductive activity? <Perhaps... could also be evidence of some sort of negative reaction to a stimulus... Did you "do something" immediately before observing this phenomenon? Like adding a chemical "supplement"? Bob Fenner>

Re: Snails I did add a third powerhead in one end of the tank where it was a little "dead," which did result in some stirring-up of the substrate in that area. Possible release of ammonia/other toxins from the disrupted LS? <Perhaps... Bob Fenner>

Astrea snails Hi! I have recently set up a 55 gal. Marine tank with 50 lbs. Live rock. The tank is pretty much cycled and I'm getting ready to start stocking fish. About 10 days ago I added 25 Astrea snails to control the brown algae that was going crazy on the rock. The snails did an amazing job of cleaning it off. Anyways, I've noticed that many of the snails like to hang out at the water line at the top of the tank. Is this healthy/normal?  <Not necessarily unhealthy or abnormal... but there may be a low oxygen situation, some other chemical, physical factor at play here... > If not, what should I do? The water quality parameters are all perfect, pH 8.2, and I've just started adding calcium & alkalinity supplements to help out my coralline algae. Thanks for your advice, Suzanne. <Be careful on the supplements... this may be the root cause... I suggest adding these to your pre-made "water change" water container, and supplementing along with this new water. Please see the section titled "Seawater" on the www.WetWebMedia.com site for particulars about pre-mixing and storing synthetic seawater, and the numerous "Supplement" pieces and FAQs about precautions and use of these materials. Bob Fenner>

Queen Conch Bob, Thanks very much for your previous help. It was so good that I'm going to ask for more. In your text on tank maintenance you seem to strongly advocate the Queen Conch. Below is your quote. "Tank cultured queen conchs, Strombus gigas are available for use in marine aquariums; suitably sized individuals scrounge around and through the substrate (and sides to a lesser extent), removing epiphytic green algae and diatom scums. Unlike their freshwater brethren, conchs will not "reproduce like rabbits" in your tank; but can reach a prodigious size of ten inches in the wild." My question is where? Where can I buy a Strombus Gigas. I have searched the web diligently and found one site that carries these animals. It sounds ok but there's a problem. The Conch is $6.00. Then there is the box charge and heat pad charge and probably a packing charge for all I know. But the thing that's a deal breaker is a minimum $48 shipping charge. No way at all! <Mail order?... I would contact the folks listed on the website: www.WetWebMedia.com on the Links Pages there... they have email... and ask what price they would charge... they're available but must be bought in "box lots" to make sense economically...> Can you point me to some other sources? <Frank Hoff, C-Quest, ORA... but don't think they sell to the "end-user" at all... once again, a matter of volume/cost/expedients... If you have a large volume retailer nearby, they might be able to combine an order with other livestock from one of these sources/breeders... Clownfishes, Gobiosoma, Pseudochromids...> Thanks... Jim Griffin <Bob Fenner>

Accidental mollusk  Hi Bob,  Thanks for the answers to my previous questions.  Today during my weekly maintenance I noticed somebody new and was wondering if he's bad news. It is some sort of brown slug, 23 mm long, with a 12 mm shell on his head. It is the kind of shell I've seen thousands of times on Southern California beaches but always thought it was one half of a little clam. It is a shallow (almost flat) triangular shape shell. He was chewing around the base of some Halimeda and squirting out clouds of white from his mouth area several times for no apparent reason.  I have him sequestered in my quarantine tank until I hear from you. Should he stay or should he go? I am planning to add one or two "beginner" soft corals in the near future if that matters.  Thanks,  Brian Battles <I say "stay"... almost feel like a latter day Caesar with my thumb up! This is likely some sort of Limpet (as in the Incredible Mr.), and I know what you mean re the many Acmaea along the coast (I live in San Diego)... these are very beneficial creatures to have in a reef tank... are microphagous herbivores that greatly aid in filamentous/pest algae control. Count yourself lucky and enjoy it/hopefully "them". Bob Fenner, By Bob Fenner, www.wetwebmedia.com>

Strombids, Culture, Contacts Bob, just curious, could you forward any contacts involved in/knowledgeable about the aquaculture of Queen Conch (Strombus gigas) from reproduction through larval metamorphosis to adult. Thanks, Chris <Nothing current in my files at home, but someone from the Philippines wrote me recently re Strombid use and his email addr. is attached to the corr. on the WWM site... current FAQs or posted to marine gastropods... and Frank Hoff should be contacted for the best folks to find NOW in the field.... You can find his firm's contact information in a recent issue of FAMA... and maybe ORA/Harbor Marine, Bill Addison/Dave Palmer... If it were me... I'd get on down to the college library, do a quick computer search and send out a few emails asking this same question to folks who've recently written (ha, recently) in the field. Bob Fenner>

Strombus species? Hello Mr. Fenner, I have read most of your articles and am a great fan of yours. I have a question regarding these algae eating snails which is abundant in our country (Philippines) as food! <Yes, have eaten them there> I have obtained a book about Philippine shells and the family Strombidae is said to be a herbivorous group.  <Principally, yes> I have seen on the market...Lambis truncata sebae, Lambis wheelwrighti, scorpius, millepeda and so on. also Strombus lengtiginosus, aurisdianae, aratrum and so on. my sand is turning brown, my question is, will they be fine for cleaning algae in my sandbed?  <As young, yes...> wont they eat the worms too? <Some, not too many> will they produce lots of slime on the tank? <Not a concern in adequately circulated, filtered systems> am going to purchase these from the wet market, will they be able to survive long hours without water? <In dark containers with material to keep them moist, yes, for a few to several hours. Better shipped this way than underwater in sealed containers> pls send email to:  thanks, Jonathan <Strombids are occasionally used as marine scavengers in a few markets internationally. Mainly as small(2-5 cm.) individuals. Most species can get too big for small marine aquarium use. Bob Fenner>

Re: Strombus species? Hello again Bob, from your previous reply, you said these are used only when small. I have about 3 inches from head to foot Lambis specie, is this not good for my sandbed? what other options do I have or what other inverts will stir sand and not sift? thanks, hope to hear from you soon. <Useful size is a "relative term"... as to the size, layout of your systems... larger Strombids can knock over rocks, corals... all are good for their "scavenging" sand sifting action. Many other animals (fish, non-fish are good sand stirrers/sifters as well) see the review on www.wetwebmedia.com. For larger systems the smaller species of Mullids are my favorite choices (Goatfishes). Bob Fenner>

Snails Hello again. A few months ago I purchased a 100lbs of aquacultured Florida rock. This has turned out to be a major haul of neat critters. I even found a 1 inch pink Chiton!!! I had always wanted to see one but thought I never would. Anyway the rock also came with 20 - 30 snails that were about a half inch or less. The snails looked like Nassarius snails with a long proboscis. They also only seem to eat dead stuff. I added a small clam for fish food and they swarmed it. Anyway now a couple of them are an inch long and the fold of their shell is starting to grow flatter and curve around their proboscis. I have looked in the Marine Atlas vol. 2. and these snails while small look like the Nassarius snails. The big ones shells look like the Atlantic tritons shell. Do any tritons have this long proboscis?  <Yes> The size limit Marine Atlas says for Nassarius snails is 3 cm. If these guys get much bigger <They do get a bit bigger> I guess they aren't Nassarius species. Do you know of any Florida Nassarius species that get bigger than an inch? <Rats! Like these mystery hunts, but am out the door to Australia... No time to look up. Do know there are snails of this sort that get a good inch and a half in overall dimension> Well thanks for your help, Everett. <Be chatting soon, Bob Fenner>

Spawning Snails Hi, I was wondering if I would be correct in assuming that if/when Cerithidae deposit eggs that the eggs appear as a whitish squiggly scroll no bigger than maybe .5 square inches? <Many, yes... some a bit larger, different colors... largely depending on what the individuals have been feeding on.> I found these at the surface of my reef almost out of the water) where I often see the snails.  I've also found them attached to fronds of Caulerpa algae, which brought to mind the thought of possibly harvesting, and rearing. The Ceriths in my tank where a lucky bonus with my live rock, and their numbers are naturally increasing slowly), which is fine for my tank. I, guess that my question would be... Is there a way/system for increasing yields. I would like to be able to raise enough of these snails to maturity to stock other tanks. <Possibly... food items, lack of predators, competitors... Trial and error I think are what I'd attempt.> I included a picture of my reef, that I'm proud to say is stocked inverts) solely with cuttings from other tanks. a big advantage to being a member of the local aquarium society!) the only wild stuff other than the live rock, is the little exotic blue/yellow Pomacentridae I "rescued" from the store. <Very nice, and good to hear.> Thanks for your time, any information is greatly appreciated. Sincerely, Cleve R. Burd Pgh, Pa. <Take a look through the WWM site: Home Page re doing computerized bibliographic searches, and get thee to a large college library... There are, little doubt, recorded observations of others that can/will aid you in your culture work. Bob Fenner>

Re: 7th grade science report. << Dear Mr. Fenner: I'm doing a report for my seventh grade science class. I found some gastropods off Topanga Canyon in Southern California. I found Ocenebra topangensis, Turritella tentlorensis and Turbo topangensis. Do you have any information about them, such as evolution background or classification details? Do you know of any publications that would be helpful to me about these gastropods? My report is due Oct. 16 and I'm having a hard time with it. I sure appreciate your input. Scotty >> <Hmm, as luck would have it, no information on me, and am visiting in the Cook Islands for a few weeks. Do have someone take you to a college library nearby and ask a reference librarian to show you how to do a computer search bibliography... much known on these organisms no doubt, and this is the place, and that is the person to help you ferret it out. Be chatting, Bob Fenner>

Nerites Hey Bob, I figured that you'd be the person to ask about contacts for getting a collection of a variety of marine Nerites. We're doing a project to look at the taxonomy of the marine Nerites and trying to get as many of the species as possible. We're having trouble locating people who can supply us with a few animals from different areas around the world. Do you have any suggestions for who to contact in regards to buying about a half dozen to 10 (preferably live, but EtOH preserved would be OK) snails of every damn species of Nerites in the world ;) Thanks a million! Rob >> <Hmm, think I do have just the person to contact (next)... Marty Beals of Tideline (Los Angeles), he and his partner Dennis Mok mainly deal in skeletons... but do have the most, best contacts for opisthobranchs, live or no. 310-641-9106, fax 649-1131 And you're welcome to say I referred you; these are old friends... Hey, not that old! Bob Fenner

Snails! Bob, About 1/2 of the snails I put in the tank (part of the clean-up crew) have died...that is, their shells end up empty and the little discs that cover them when they go into their shells end up on the gravel. I remove the shells...some stink and some do not. I think the crabs go after the remains of the snails. <Maybe the "befores" as well...> Anyway, this morning before the lights came on I noticed a couple of dozen small snails on the glass! I suppose the snails could have multiplied, right? Later, after the lights came on, most of them "disappeared." Of course, they have not left, but they are small enough they can blend into the rocks quite easily. <Maybe... perhaps these are others that were on your live rock...> Is it normal to have snails reproduce like this? How long before they get bigger? I am curious because I'd like to have more snails, but am reluctant to buy more if there are so many little ones about. <Depends on species... and the real net causes of the others mortality... May be a predator or two in your system...Alpheid shrimps, mantis... many possibilities... Or, a chemical "imbalance"... most likely a lack of biomineral and/or alkalinity... very common causes of loss.> John >> <And you. Bob Fenner>

Snails Hi Bob, Where have you been? I haven't been able to find you in the usual places (FFX).  <Still here, on the planet... traveling quite a bit, and answering queries for the new masters: Pets.com...> I hope all is well. I've got a couple questions about snails imported on my live Fiji rock. I have at least two snails in my tank. They are about 1/4" long. Their shells are a white and brown checker-board pattern. They seem to be eating the algae on the glass. Here's the questions.... 1 - Are they any threat to any type of invert? <Not likely> 2 - If yes, do they reproduce rapidly? <Probably not... considering rate limiting factors... food, substrate, competition, possible predation> 3 - Can I remove them with a reef safe predator (preferably colorful/interesting if possible) or do I have to remove them by hand? <Leave them be IMO... likely self-limiting, maybe even helpful>  I've looked through al of my books and couldn't find any info/ID on these snails. I just brought the rock into my show tank, and if these guys are a problem, I'd like to take care of them now. Thanks and hope all is well, Tony Revinski >> <No worries mate... be chatting. Bob Fenner>

Re: Snails Bob, Thanks for your quick reply. I'm unsure of your answer to #3. Do you mean not necessarily any snails and hermits, or you would use something other than the Astrea? And you don't like stars for cleanup or not at all? Thanks again, Steve <Hmm, let's see if I can be a little clearer here. I mean/meant not necessarily any snails or hermits (some folks use other types of cleaner-upper organisms)... and I sometimes do use Astrea snails, in addition to other species (like Margarites)... and I don't like BRITTLE Stars in general, but other species can be of great utility... Some of the Brittles are fish eaters, other trouble-makers. Bob Fenner>

Snails I have a couple of different types of snails and was recently encountered with hundreds of this little black and some blotched with white snails. They have long pointed shells. Are these a harmful snail and if they are how should I rid them. I was also wondering what information you could give me about the 6 line wrasse. I have many hard and soft corals and don't want to enter anything damaging into my system.  thank you for your time.  >> Hmm, these snails may well be Pyramidellids... and if so, you'll be more than glad to have the excellent Six Line (Pseudocheilinus hexataenia) in your tank... this little dynamo eats these possibly pesky snails (esp. problematical for folks with Tridacnid clams)... What's more, this wrasse species eats many types of "commensal" flatworms. About their only downside is being ultra-shy. Bob Fenner

Too many snails? Hi Bob! I have some new snails that seem to have come in on my last piece of live rock...they have a conical shape, white shell with black spots in rows around the shell. I first noticed 1 or 2 when they were really small. Now I have 18 to 24 and it seems I see more every day! They start out about the size of a grain of sugar, but seem to grow rapidly. The largest one is now about the size of a pencil eraser... They seem to thrive on algae and there is plenty to go around. I have a half dozen Mexican Turbo Snails, about 6 Trochus, and 10 Bumble Bee snails... do you think these new guys will equal out like you have mentioned about other inverts? <Hmm, well, sounds like some sort of Trochid... "Wavy top snail" species... I would keep my eyes on them... just in case this is some sort of soft coral, giant clam chewer... But not go so far as to try and eradicate them at this point... may well be commensal, to beneficial> I really get a lot out of reading your Daily Q & A's and your book "The Conscientious Marine Aquarist" is awesome! So much to absorb! <Yes indeed> This month is my first anniversary of owning a salt water system and everything is going great thanks to the great wealth of knowledge that's available from people like yourself! Thank YOU! Greg Warner <And thank you for your participation in the hobby, this forum and engagement with the living world. Bob Fenner>

> Hello Bob, > Still have 4-5 weeks before my main tank is delivered, but as usual I have a few questions. > 130 gallon(68x18x24). >> 1. What is your opinion on the use of Polydiscs in the inline canister instead of carbon. > <I'd use both... two different purposes... the former just leave in place, cycle a unit of carbon in/out once a month> > 2. Do you know anything about the Neptune Controller II and do you recommend it? > <Yes, am familiar with the product. No specific recommendations... there are > other competing lines, in particular the Octopus by Aquadyne... take a look about, there are sites that compare, contrast controllers... Detail what features you're looking for, seek out users' opinions on the functionality of probes...> > 3. 130 gal. reef with 120 lbs. of LR. How many Astrea snails, hermit crabs, and brittle stars? > <Not necessarily any... if I were going the Astrea snail route, about fifty, > hermits about the same... No to brittle stars for my systems...> > Any reason to quarantine any of these in a new tank with no plans for > fish before first part > of July? Quarantine tank is up and running. > <Maybe just a day or two to make sure everyone's alive... move them in as > they move...> > 4. Wet dry in main tank will be 30x12x18. What % of this should be LR and how > many watts light > is needed? > <A third to half on the live rock, twenty to forty watts> > Thanks again for being there. It's nice to have someone that not only can > get you through tough > spots, but comes across as not just a person doing their job but a friend. > Best, Steve > Indeed, it's because I am,  Bob Fenner

Algae How much algae will two turbo snails graze from a 37 gallon aquarium? Should I buy more? Also, how can bubble algae become a nuisance? >> Hmm, you need a bunch more... depending on how much of what types of algae they might eat you have.... (some syntax now!). And what other "algae eaters...". You could place another dozen easy. Bubble algae can be a problem as being unsightly, crowding out desirable forms of life, some of its physiological byproducts are toxic... some's no problem... Bob Fenner

Nassarius snails and brittle stars  I recently purchased some brittle stars and I was wondering if they will get along with Nassarius snails or will the stars try to eat the Nassarius since they are so small.  >> Wowzah, there's a genus of gastropod mollusks I haven't heard in a while... It's a possibility... some of the brittle stars are really ravenous predators... Bob Fenner

What do Tiger Cowry's eat? Is there a resource where I can look up things like this? >> Of the two hundred or so mollusks that are cowries (family Cypraeidae)... most feeding habits are unknown... For Cypraea tigris, small ones don't need to be specifically fed... larger specimens are predators and detritivores... and readily accept bits of fish flesh, mussel, pelleted dried-prepared foods (placed near them)... You might start with the Baensch Marine Atlases as a good, solid invertebrate reference. Bob Fenner, who has hunted for Cypraeids a few places in the world.

Dead Snails I recently moved. Both houses are on wells. In the new house snails die almost instantly. Standard water tests have not revealed any insights. Other fish and inverts have done fine. Do you have any suggestions. >> Yes I do... get/use a Reverse Osmosis unit for cleaning up your source water... for fish and your own/drinking, cooking use... Could be "just" saturated gasses in the well-water, or somethings' more permanent... If I "lived there" I would have my water checked by an independent lab... to ascertain what's in it... And definitely, I would/do use an RO myself... Bob Fenner

Hitchhiking invertebrates Dear Mr. Fenner, First of all, thanks to your previous advice my 29 gallon aquarium is now running smoothly. It is turning into a source of great pleasure. I have stocked it with 45 lbs. of live rock, aquacultured in the Gulf of Mexico. There is an array of life on the rocks, including barnacles, blue legged hermit crabs, and some I can not identify. These are what concern me. I have some gastropods, with cone-shaped shells and necks about the thickness of pencil lead that can protrude as much as half an inch. The necks are dark, sometimes with white spots. In trying to identify them, I have read (including from your book) that cone snails are to be avoided. As they are already in the tank, should I attempt to remove them or just leave them alone? There appears to be a number of them, and I have seen several minute ones as well.  Also, is there such a critter as a brown Mithrax crab? I have seen, only  recently, some small brown crabs with hairy legs.  The only livestock I have purposefully added to the tank are a cherubfish (C. argi) and a Sally lightfoot crab. So far, none of the hitchhiking  invertebrates seem to bother them, but the crabs are still very small. As always, thanks in advance for your time and advice. >> Hmm, do like these mystery "what is this" questions... but don't know what "they" are specifically very often... I wouldn't sweat the apparent snails or crabs (likely not Mithrax), lest the latter start getting really big... and "into things". Stay on your stocking path as if these "recruits" didn't exist... Amazing the stuff that comes out of liverock eh? What a planet! Bob Fenner

Response to readers question today QUESTION: I have a 55 gallon saltwater tank in which I placed rock about 2.5 months ago. I noticed a black snail like-creature a couple of days later and thought that it was cool. It was eating algae and I liked that. Then about a month later I noticed another that was tan and didn't think much about it. Then about a week ago I was looking closely at the fish feeding and noticed a bunch of little creatures similar to the big ones and I became concerned.  These things are reproducing at an enormous rate. I don't want them anymore and I certainly cannot remove them all by hand. (I have removed the two large ones.) I really don't want them to overpopulate my tank and kill off all the stuff I do want.  These creatures have a flat oval shell, and are hard to remove from rock and mostly come out at night. Is there anything that will eat them?  Bob's Answer: Hmm, hard to define exactly what you have... some sort of snail or a species of one of several worm groups. Yes, there are a number of celebrated potential consumers to try. In order, I would place one or two Peppermint Shrimp (Lysmata wurdemanni) or a Six-Lined Wrasse, (Pseudocheilinus hexataenia).  I too have these ? shell snails. They breed quickly when there is plenty to eat. Over time they will level out once the food is gone. I've had them for about 2 years now and they don't seem to be doing much except keeping the rock clean and aiding with the glass. I do notice a slight rise in population when I add new live rock, but it usually doesn't last too long. Very rarely do I ever see them during the day either. Actually they are like little elves who come out and clean the house at night and leave it for my enjoyment during the day, unlike my other snails that park themselves on the front of my glass when company comes. My corals are doing great so I wouldn't say the snails are bothering them at all.  Thanks, Jeff Phillips >> And thank you, Jeff, for the further input. Bob Fenner

Snail My Astrea snail is secreting a milky substances from itself. Should I take it out? Or is releasing sperm or something like that? >> Probably the latter... if it is still moving about, leave it be... if it stops moving for a day, the heave ho. Bob Fenner

Snails As allies against algae I understand they are great, but do they reproduce and become an intolerable nuisance in marine tanks like they do in freshwater ? Would a few extra crabs or an abalone work just as well? thanks. >> Hmm. Well, unlike some of the popular freshwater snails, the marines very rarely get into reproductive mischief... Some, like Astrea snails are especially helpful as algae controllers... Most crabs (true ones, as opposed to false, like some of the helpful small hermit species) are problematical... And for the most part, Abalone are not of practical use in "micro-algae" control in tropical marine aquariums... Many species/specimens sold are cool water macrophagous herbivores... There are MANY other purposeful algae eaters for marines... but the best approach to algae control is proper set-up and maintenance... Bob Fenner, whose articles on these topics can be found at www.wetwebmedia.com

Snails Here's a new one for you. Last night around 11:30pm I was watching a show on Discovery about the ten most venomous sea creatures. Low and behold number ten was a snail (I don't remember the name). This snail had a long snout and poisoned its victims with a sort of barb then sucked them from their shell. Now for the real kicker - this morning I found something similar in my tank. It has black shell with a white striping pattern and a long snout. The fleshy part of the snail also has this black and white pattern. My question is: could the snail I have be a snail/crab/fish eater too? Possibly the same family? Should I remove it before it immediately? >> Hmm, small doubt you're referring to some of the Cone Snails (e.g. Conus geographicus, family Conidae)... have a few books, and shells of the family in my collection... but of the more than 300 species described, none as you detail (maybe the Hebrew Cone?, Conus abraeus). Anyhow, I doubt if this is a toxic species, and if it were in my tank, I'd leave it there.... More likely, if you are losing animals mysteriously, that a crab, serpent star, mantis shrimp, bristle worm species... involved. Bob Fenner

An Abundance of Snails Bob: I have recently experienced a population explosion of small (1/16th to 1/8th inch in length), off-white colored snails, that only come out at night. I have not added any live rock to the aquarium in a year but I have been increasing the calcium levels in the tank recently. I have never seen these snails before but I believe that I have changed the tank environment such that these snails have been able to exploit it. During the day, I cannot see even one of these snails but at night the walls of the tank are crawling with them. They appear to be coming out of the sand bed, which was not a live sand bed, until they showed up. I have at least a hundred of these little algae eating dynamos in my tank. They seem to relish the green film of algae that grows on the walls of the tank. Do you have any idea of what type of snail this is or where to look for information? Appreciate any thoughts! Martin >> Well stated... and you're probably fortunate to have these cleaner uppers... The species... or even the family is hard to establish from the description... There are over 35,000 species of gastropod (snail) mollusks described... To begin a search for identification... the Net under the words "snail", "gastropod" and further modifier "taxonomy", "identification"... would be my starting point. There are Field Identification books that are part of the hobby press... but I don't think they will avail you much ( have just looked through a few )... I would encourage you to move some of the substrate and these snails to another system... as it is certain that some unseen/perhaps unseeable event will bring about their total demise where they are presently/solely... If you are interested in eradicating them, A Lined Wrasse species will be an easy choice. Bob Fenner

Question about the supply of limpets. Bob: It seems that I have purchased some Man made Florida rock here and there and received some very unusual creatures called Limpets. I i.d.'d the critter from "The Modern Coral Reef Aquarium" Volume 1. Svein A. Fossa & Alf Jacob Nilsen. An example of the scientific name and picture on Page 188 is Scutus unguis. And yes the animals look very close to a Nudibranch, except they carry a cone-like shell that looks like a volcano. Some species cover the shell with what looks like a mantle. These critters seem to mow down more hair and slime algae than 5 or 7 turbo snails together. Q: Where may one find a supply of these? None seem to be listed on the FFE web pages? I still have one that looks more like a moving volcano that does not wrap it's mantle, and the other was flame orange that did wrap it's mantle. And it looked just a Nudibranch of sorts. Very pretty!! But the seem not to like medications. This animal seems to be very low maintenance and very tolerant of water quality, versus what most Nudibranchs require to stay alive. Am I looking for this animal in the right place? CH >> Well, I looked around for limpets as well and couldn't find anyone listing them for sale... But do want to say a few things about them. I agree totally with your observations... and assessment... these Archaeogastropoda are great and innocuous cleaner uppers. Having worked with local (S. Calif.) limpets with different projects, I suspect that they're not specifically offered for two reasons: They're hard to extract from hard substrates w/o damaging them... and Folks just don't know about their usefulness as yet... Unlike Nudibranchs, many limpets have wide, generalized diets (micro and macrophagous herbivores)... and also unlike the "naked gill gastropods", they don't have a tendency toward toxicity... Instead of being poisonous, limpets have a shielding "home" on their backs... and lastly, as you observe, many live in "marginal" and variable environments in the wild... and are therefore reasonably tolerant of the same in captive situations. Thanks for writing. Bob Fenner

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

" Horse Conch" ?? Hi  I was recently in Florida and picked up a shell that contains what people have told me is a horse conch. I'd like to know if that is indeed what I have. I will try to describe it to the best of my ability. The shell is a dark brown, spiral about 4 1/2 inches in length. The conch inside of the shell is an orange color. I found it on the shore in a sandy area with seagrass the had washed up. I understand that these creatures could grow quite large, perhaps 2 ft.? I've also been told that they are algae eaters. Other than the fact that it lives in salt water I know nothing else. Anything you could tell me would be appreciated. Thanks much >> Might well be a Florida Horse Conch, Pleuropoca gigantea... These are decidedly more spiral and long (conical) than the "other" tropical west Atlantic Conch species (genus Strombus)... Common in Bahamas and Florida... live in seagrass beds as young, deeper water for adults (DeLoach & Humann). Principally algivores, will take commercial prepared foods like tablets that are algae-based, as well as bits of fish and mussel. (Baensch Mar. Atlas 2). Bob Fenner, who knows that people sometimes keep cultured Queen Conchs (S. gigas) for algae control... as young, and in large systems... but has no experience with Horse Conchs.

I have a 170 gallon reef Jaubert filtration. I also think I have a snail problem , possibly with Heliacus areola which I identified in The Reef Aquarium book. I removed at least 100 of these guys in about an hour, any suggestion on control of these little guys would be greatly appreciated. THANK YOU! Robert White >> Oh boy, some exercise now! In order to prescribe a predatory cure I'd like to know what other livestock you have... There are some fishes and invertebrates to consider... but they may be deleterious to your existing life. Bob Fenner <<  Also Three clams a Tridacna crocea, and 2 T. maximas.  >> Okay then (sort of like Gump today), I'd look into a small wrasse species of the genus Pseudocheilinus (the lined wrasses)... the four, six... lined species, maybe an evanidus... try one each of two species for your 170 gallon. Bob Fenner