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FAQs on Chitons 1

Related Articles: Chitons, Mollusks, Sea Slugs

Related FAQs: Chitons 2, & FAQs on: Chiton Identification, Chiton Behavior, Chiton Compatibility, Chiton Selection, Chiton Systems, Chiton Feeding, Chiton Disease, Chiton Reproduction & Mollusks, Sea SlugsSea Slugs, Marine Snails 1Marine Snails 2, Marine Snails 3

Hitchhiker ID: Polyplacophoran/Chiton - 10/10/07 Greetings WWM Crew! <Greetings, and good morning to you as well!> I dug through the hitchhiker ID's in the FAQ and didn't come across this one (maybe I just missed him?). Pic is attached, came in with a colony of Zo's - he's a pretty mean looking guy, fuzzy with spikes running down his back. <It does look a bit intimidating, doesn't it? Heeee.. you can name him/her Spike! The good news is that this is a neat little Polyplacophoran, or Chiton. They're herbivores/mostly algae grazers, reef safe, and nocturnal. I'd be curious to find out where this little guy arrived from, as it looks very similar to the species Cryptoplax striata (see this link for comparison: http://fjas.nl/cryptoplstriata.htm ). Additional general information here: http://www.wetwebmedia.com/mollusca1.htm http://www.wetwebmedia.com/chitonfaqs.htm I have one last link for you because it's just too great not to share. It's a species list with some terrific images of live Chitons: http://fjas.nl/livingpolyplacophora.htm . Enjoy your new addition!> Thanks! <You're very welcome! -Lynn> Dave

Hitchhiker ID: Polyplacophoran/Chiton Follow-up - 10/10/07 <Hi Dave!> Thanks Lynn <My pleasure> - the one in that first link you sent looks just like him. <Excellent. That's a pretty little Chiton.> Spike has been moved to a happy new home in our 150 gallon live-rock sump - it's a lit sump, so lots of algae to graze on. <Good to hear. Chitons graze on hard surfaces, so it sounds like he'll be fixed up.> He came with some Zo's from Fosters and Smith, no idea where they originated. <LOL Yep, no telling. Those Zo's could have been in a holding tank with specimens from all over the world. At any rate, it sounds like Spike's got a nice new home!> Cheers,
<Glad I could help. Take care - Lynn>

Cryptoplax, Chiton ID, aquarist input/help    9/25/07 Hi, <Enrico> Do not know, if you meanwhile solved the identification of the Cryptoplax you found from a tank. The species is Cryptoplax burrowi. Compile a distribution database for Chiton species, so would be interested if you could provide detailed data, and if you came across other species. <Mmm, what little WWM has re Polyplacophorans is posted here: http://www.wetwebmedia.com/chitonfaqs.htm> Cheers, Enrico <Danke, Bob Fenner> -- Enrico Schwabe Zoological State Collection Munich (ZSM) Dep. Mollusca Muenchhausenstrasse 21 D-81247 Muenchen Germany field of work: world-wide Polyplacophora (main focus Indo-Pacific) http://www.zsm.mwn.de http://www.worldwideconchology.com/BaliChitons.html

Chiton Pix   9/12/07 Good afternoon, <Now early morning.> I know you guys like pictures. <Yep... I like to take'em too!> So how about some of my Chiton buddies? They're really cool. My invert-guru friend says that these ones are probably intertidal and that's why they're not afraid to craw in and out of the tank. <Heehee! Cool pics. These guys would likely become kitty toys in my house!> Sara M.
<Hey... aren't you part of the crew? ;) Mich>


Chiton...  7/31/07 Hi guys... <Hi Jo, Mich here.> Can you please tell me if this guy is a Chiton...he's around 2inches long and flattish...there's plenty of pics around of the shell side of these critters, but none showing the mouth etc...I took him out of my tank just in case he was a baddie, but if he's a goodie, he can return... <Does look like a Chiton to me. More pics here: http://www.wetwebmedia.com/chitonfaqs.htm or do a Google image search using "Chiton" and "ventral".> Thanking you...
<Welcome... Mich>

Chiton, and possible quarantine  5/27/07 <Hello Kent, Mich with you today.> I live in Australia, on the east coast, <Lucky you!  I live in the USA, on the east coast.> and today happened upon a nice piece of dead coral.  Thinking I could use it in my tank I will soon be setting up, I took it home and put it in my QT.   <Starting the right way!  Good for you and all the future creatures in your care!> Well, now I have a 2-inch Chiton crawling around in the QT, and I was wondering if there would be a problem with introducing it into my existing tank.   <No, not likely to be a problem.> I am worried about disease being introduced, but have not seen anything on this using your site.   <I am unaware of Chitons posing much threat as a vector for disease.> Would this be a good idea to put it straight in?   <I would keep it in your QT tank for now.> Thanks for any advice you can give me, really enjoy your site. <Welcome and glad you like the site!  Mich> Kent

Name that Invert :) ...In six notes or less: Chiton   5/23/07 Hi Crew <Hi Jackie, Mich here!> I was hoping you could help me identify this invert that I purchased.   <Better to ID first then purchase.> I am very new to reef keeping and have been researching every animal that I have.  This one, I cannot find anywhere.  It seems kind of like an abalone in that it has 4 small holes on top of its back. <Hmm, Chitons typically have eight.>   However, it does not have a shell.  More like a leathery smooth back.  I am enclosing a pic, but I apologize it isn't very good.  This is what I have observed.  It is nocturnal.  It is grayish, brownish, green colored with dark brown stripes around it on the fringe/feathery area (cerata?) below the mantle but above the foot.  Its shape is oblong with perhaps a bit of a point on its rear end.  It has two rhinophores (striated bulbs I think).  It spends almost all of its time on the live rock, but sometimes ventures to the glass, stays low in the tank anyway.  I have not seen it on the substrate ever.  It can retract its head into its mantle - when it is resting or frightened it pulls itself into the mantle and appears more circular/oval in shape.  It can be somewhat flat (1/8th inch perhaps), but have noted a few instances where the foot/ underside seems to almost inflate such that it doubles in width.  I have trouble thinking it is a Nudibranch since all that I have seen suggest they are quite colorful - this invert is almost hard to see when it's on the rocks.  It doesn't seem to have a shell even though its top is smooth and seems thickish.  Nothing else in the tank bothers it.  For the longest time it seemed to spend all its day time resting in the crevice/cave that my Daum reef lobster hangs out in during the day -  oddly, since the lobster is very possessive of it's lair and nothing else seems to be able to even approach it without getting snapped at.  It seems to feed off the rocks/glass and I have not seen it bother any snails or my crab or clowns.  It rests upside down almost exclusively.  It is about two inches long and about half inch across, eighth inch width I guess.  So I hope this helps you to help me find out what this creature is.   <I believe you have a Chiton, though a limpet might also be a possibility, but I'm leaning toward a Chiton.  More here: http://www.wetwebmedia.com/chitonfaqs.htm > What is its diet?   <Chitons are herbivores.> Where does it come from? <Chitons are found in all seas.> I tried to find out more from where I got it at the pet store but I am now doubtful of the knowledge of the staff there since they also sold me a sand sifting tiger star and I have neither the substrate depth or tank size to sustain it (I am going to try to exchange it).   <It is always best to do your own research before making any purchases.  Unfortunately, sand sifting stars typically starve to death in captivity.> My tank is 20 gallons.  I have about 10 pounds live rock.  Aragonite substrate about 1.5 inches.  Rio Nano Protein Skimmer.  Aquaclear hang on filter with foam and carbon inserts.  Elite hush hang on filter with BioMax in place of cartridge.  T5 Glo Daylight and Actinic lighting.  Tank occupants are Red Mithrax Emerald Crab, Green Bubble Tip Anemone, <Mmm, I personally am not a big anemone fan.  They like to go for walks at the most inopportune time, which can spell disaster, especially in such a small system.> Daum's Reef Lobster (purple), <Should be in a larger tank, closer to 50 gallons.> Two false Percula, Sand Sifting Star, 3 Star Snails and one bumble bee snail that is currently missing in action.  Water parameters are all good.   <Vague.> Using RO. <Good.> Salinity is 1.026.  Temp is 80.  Thanks for your help. <Welcome!  Please do get in the habit of researching prior to purchasing.  Mich> Jackie

Re: Name that Invert :) ...In six notes or less: Chiton   5/24/07 Hi Mitch <Hi Jackie, Mich with you again.> Thank you for your prompt reply.   <Welcome!> Please know that I have definitely learned a lot of (hard) lessons since setting up my reef one month ago.  Rest assured that I will never purchase another animal for the tank that I haven't researched in full.   <Glad to hear!> I was just taking the advice of the LFS staff who just said yes or no to compatibility when I pointed to stuff in their show tanks.  The learning curve to marine tanks is steep.   <Yes, there is always something more to learn.> This site has been a plethora of info for me. <And everyone else!> I agree that the invert is likely a Chiton.   <OK.> The thing that bothered me about giving it that classification is that I could not see eight holes on top and it does not have identifiable plates.   <Some look fleshy or leathery.> In fact last night I think I saw more like what looked like a whorly type of lineage on its mantle top. <Possible.>   It was on the front glass last night and I saw the bottom is very smooth and very much like a Chiton.  It has a fairly large orifice for a mouth, with what looks like a red radula? <OK.> Thanks for your help.   <Welcome!> Water parameter last nights test Nitrates and Ammonia are somewhat elevated at 5.0 and 0.25 respectively <Zero for both is optimal.> (I think since I have been overfeeding in fear that the sand sifting star will die before I can take it back) <Shouldn't starvation is typically a slow death.> Nitrites 0.00 and pH 8.2.  Temp 80.  Salinity 1.025  Have a bit of brown algae still and some of it is a bit like hair.  Substrate these days looks a bit littered with rusty patches?   <Nuisance algae, Likely Cyano/BGA.> I feed HBH Flake Frenzy for the two false percula and HBH Super Soft (about 5 pellets a day).  Every other day I give a quarter square of frozen Mysis shrimp. (Which I try to squirt with a baster around the bubble tip)  Too much?   <Does sound like a hefty amount for a twenty gallon tank.> The clowns always look hungry. <My cats always look hungry too, and will eat to the point of vomiting if allowed.> A few other questions - I have the Master Saltwater Test kit, which tests nitrates, nitrites, ammonia and ph.  What other tests should I purchase? <Likely Calcium and Phosphate.  Would consider other brand names as well... more here:  http://www.wetwebmedia.com/mtestbrands.htm > Since I am now using RO water exclusively, what kind of buffers do I need or do I? <pH/Alkalinity, Calcium more here and related links in blue: http://www.wetwebmedia.com/marphalk.htm http://www.wetwebmedia.com/alkalinity.htm http://www.wetwebmedia.com/caalkadds.htm > Thanks again!   <Welcome again!> Happy fish keeping.
<And to you!  Mich>

Strange Critter ID Please: Chiton   5/10/07 Hello there! <Hi Jo, Mich here!> I know that you guys are really busy but I was hoping you might be able to help me ID this critter. <Certainly will try!> We are currently setting up our second reef tank. The LR is from Indonesia as far as I know and this "thing" has showed up twice now, both times at night with all lights off. It seems quite shy and retracts slowly back in its hole as soon as the room light is put on.  I find watching the LR and the critters on it one of the best things in this hobby. <Heee!  Yes, I would agree.  One of my favorite parts too!  When I was setting up my tank most people just didn't understand when I would tell them how excited I was watching all the life emerge from the LR.  I would get comments, with undertones questioning my sanity: "So you've spent the last hour staring at rocks?" > We had new forms of life coming up in our 2.5 years old reef right up to the end and managed to ID most of them but this is really unusual. Any thoughts? It is flesh colour and I thought it was some sort of bivalve but it seems quite soft, a bit like an anemone. <Looks like a Chiton to me.  They are reef safe and generally graze on algae.  A lucky addition!  Do enjoy it!> Many thanks for your time and looking forward to hearing from you soon <Welcome!  Mich>
Best regards,
Jo Vasey
Re: strange critter ID please photo now added, Chiton     5/12/07 Hi Mich and thanks for the quick reply! <Hi Jo!  You are quite welcome.> Are Chitons what some call "Stomatellas" (please forgive me if I've spelled this wrong)? <No, they are two different critters and your photo is not a picture of a Stomatella snail.> I did a search on Google but the critter doesn't look much like the search returned on Chiton - the main difference being the lack of a shell on his back. <Many different species, not all have the "classic" Chiton look.> The 2 black holes/openings look a little bit like craters? <I think you will find there are more than two "holes", there are likely 8 "holes" or eight linearly arranged overlapping articulating plates, which make up the shell on his back.> Any more thoughts? <Nope, I still think it is a Chiton.  Please see similar photos here:   http://www.wetwebmedia.com/invertidfaqs.htm Chiton ID 9/9/03 and here: http://www.wetwebmedia.com/snailidfaq3.htm Prehistoric worm...errr...??????? 1/30/04> I think I saw it last night quite longer and stretched inside the rock which is very porous and you can see through but could be wrong. <Likely so, they do tend to stay in the same location emerging typically at night to feed.  The behavior you described in your prior email is also consistent with a Chiton.> It is really bugging me now. My LFS is kindly looking after my livestock during house move and upgrading the tank. We are getting our corals back soon - I am trying to decide if I should remove the piece of rock with the critter to the sump where it won't be tempted to munch on anything? <Most are harmless algae eaters.  If it were me/mine, I would not be concerned.> Many thanks again and looking forward to hearing from you again! <You're welcome!  Hope this gives you more confidence in the ID.  Mich> Best regards
Re: strange critter ID please photo now added... Polyplacophoran   5/12/07 Hi Mich, <Hello again Jo!> Thanks for the links. <You're welcome!> Yes, it looks very much like the one in the first link and thanks God it's not 6" (yet!) like the one in the second link. <Heee!> Thank you for helping me ID it, I didn't mean to doubt you but my not very in depth search on Google returned completely different images. <I can appreciate and understand.  And just found another photo here:   http://www.wetwebmedia.com/invertid24.htm Can you identify  3/16/2007 > As for the 8 "holes" I did think that there might be more than 2 but couldn't see properly as it wouldn't come out of the rock enough to see properly. <Yes, Chitons can be quite shy.> I will continue to observe it and will try to learn a bit more about its feeding habits. <Excellent!> Many thanks again! <You're quite welcome!  A pleasure to assist!  Mich> Jo

Look's like a Chiton - about 6 inches... images an order of magnitude too large... PLEASE> FOLLOW DIRECTIONS!!!  - 2/26/07 I own a copy of your book as it saved me when I first got my tank from making a lot of mistakes.  I have elevated my knowledge in the last year alone and added two more tanks to my system and have used some GARF products to help to boost my tanks performance. <Brad, you've crashed our server...> We had a power outage for over 24 hours and I kept as many of my fish alive as possible.  In the end I lost two including a black clown that was being eaten by a crab in the picture.  I usually would not let the crab eat a fish, but I wanted him to leave the sluggish tired fish alone in the tank as my batteries had run out and a generator was still hours away. I found this critter doing a hot lap past the crab and clown that appeared to be a Chiton.  I was curious though as it changed color to a darker brown and kind of green one subsection at a time right as it approached the crab eating the fish.  I watched in anticipation, but in the end it just kept scooting on out of site.  I have never seen this guy before and he is fairly substantial in size.   I took 32 pictures of this guy, these are some of the clearer ones since I was shooting through the gals of the tank.  I didn't want to take him out since he appeared harmless to my tank inhabitants.  That is until proven guilty as I have been removing Zoos from this tank since they were not fairing well for some reason? Let me know what you think,
<Is a Chiton. Bob Fenner>

Invert Ident:  Woodlouse on Land = <Actually doesn't equal> Chiton by Sea.  1/31/07 Hi Crew <Hello Darren, Mich with you today.> First time questioner and marine newbie! <Welcome to our salty world!> When re-arranging some rock in my recently set up 42 gal, I noticed a strange creature - about 1/4 - 1/2 inch long, pale coloured with a yellowish end, slow moving and segmented like (and reminiscent of) a woodlouse, although with no visible appendages. <Hmm, very interesting.  I have never heard of a woodlouse.  I did a search and now I can ID your critter.  I had no idea there was something so similar on both land and sea.  What a world!  You've got to love it!  What you have is a Chiton.  For more info, please read here:  http://en.wikipedia.org/wiki/Chiton  > Worth worrying about, or just another example of nature's diversity imported on live rock! Just another example of nature's incredible diversity, a fine reef safe addition.  Lucky you! Thanks and keep up the sterling work! <You are quite welcome!  Thanks for teaching me something new today and for reminding me just how amazing life is on our planet!  -Mich> Darren

Unknown creature... Chitons in Cozumel   1/30/07 <Hi Tracy, Mich with you today.> While vacationing in Cozumel Mexico we saw these strange creatures attached to the rocks by the water.  My Uncle is quite curious as we all are what they are and the back ground on them, if you could help me. <These are Chitons... living fossils.   You can find more here:   http://en.wikipedia.org/wiki/Chiton  > Thank You, <You're welcome.  -Mich>      Tracy McCullin

Source for Chitons?  12/1/05 I've search through your site and many others looking for a possible source for purchasing a Chiton. I've been fascinated by them since tide-pooling in a marine inverts class several years back (more than several actually).  Any hope that you know of a source for these neat creatures? Other than hoping to get one hitching a ride on live rock.  <Other than a hitchhiker, I know of no source. I'm sure one can be special ordered from a LFS. Dealers don't stock inverts like this because there isn't a demand for them. James (Salty Dog)> <<Maybe GARF, or another supplier if "clean-up" crews, perhaps?  Marina>>

Chitons in the Reef Tank. Hello Kind Sirs, It's been quite a while since I sought your advice; for the most part things have been going very good.  Low and behold last night I notice a new inhabitant slowly crawling on my live rock. This little beastie is about 1.5 inches long with what appears to be a flexible segmented center shell surrounded by the white and purple mantle. The tank has been up and running for a couple of years the live rock was from Walt Smith and has been in there for well over a year. Soft Corals, cucumber, starfish shrimp and fish all doing fine so I don't think he's doing any damage??? I've been an avid reader of your website for quite a while and I don't think I ever seen anything quite like this guy. He does look pretty cool and I'm guessing some kind of Chiton. Any idea if he's a good neighbor or should he be banished. Chuck >>>Hello Chuck! I just love those Chitons, one of my favorite marine inverts. I think it's all the time I've spent tidepooling over the years and finding those little guys. Anyway, no worries. They are algae/surface film grazers for the most part, and not a threat to your other inverts. You're quite lucky to have such a large individual, as most hitchhiking Chitons are quite small. I have several small specimens in my tank currently. Cheers

Chiton Questions 3/26/04 Hello Bob, I am a member at Reef Aquarium Guide and I am trying to find information if there is possible a bad hitchhiker Chiton that can arrive on live rock. <hmm... Chitons are overall very very "reef safe" as algae grazers. Limpets are often confused with Chitons and can be predatory no reef animals. Are you sure it is a Chiton?> I have a 125 gallon reef . I watched as my post prized zoanthids disappeared over a few days time. The rock is mostly covered in coralline except where the polyps were  at. I noticed a bright pink to purplish bumpy spot on the rock. I watched the rock for several days and the Chiton finally moved. I took the rock out immediately and took the Chiton off. <yes perhaps> I had 2 huge rock with polyps disappear in 2 days time. The Chiton was the only thing on the rocks. Any info you can give me would be great.   Vicki <without a picture of the animal, there is not way for me to be able to ID/confirm. There are many possible predators on your zoanthids. Do keep an eye out for Prosobranch snails instead of your suspect polyplacophorid. Anthony>

Help with identification Hi, I'm trying to figure out what this is.  I found it my reef tank last night.  I showed the photo to my LFS and they told me it could be a Chiton, Cryptoplax or Stenoplax.  I've looked hard doing google searches to find exactly what it is to no avail.  Do you think it is reef safe?   >From what I can tell so far it grazes on algae. Thanks in advance, ART KOUNS <It is definitely a Chiton of some species... and reef safe enough (an algae eater. Bob Fenner>

Re: Help with identification thanks, it narrows it down slightly.  at least i appears to be reef safe.  it's kind of funny this was the first time I've seen it being that my tank has been going for 2 years. <Amazing, but happens "all the time"... and testimony to your consistent good care. Bob Fenner>
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