what is this? A bivalve  – 10/10/08 I just had a question about something that has appeared on my live rock. I noticed a little tiny clam like thing growing on my live rock I just wasn't exactly sure what it was. I thought it might be a scallop. If you could identify it better than I could that would be very helpful. <Is... a bivalve... akin to that shown here: http://images.google.com/imgres?imgurl=http://www.timespub.tc/fileadmin/user_upload/featured/Fall%25202004/Shell%252054.jpg&imgrefurl=http://www.timespub.tc/index.php%3Fid%3D41&h=306&w=200&sz=10&hl=en&start=21&um=1&usg=__SU0UmajdRQ8AMYmVpmNXv-ve2uU=&tbnid=dfMqOgjeJlVwQM:&tbnh=117&tbnw=76&prev=/images%3Fq%3Dupright%2Bbivalves%26um%3D1%26hl%3Den%26rls%3Dcom.microsoft:en-us:IE-Address%26rlz%3D1I7PCTA There are similar species in all tropical to cool water oceans> Also, I didn't know how big it would get or if it would be harmful to anything in my tank. <I doubt it will grow very large in this setting... relies on filter feeding/foods... and not deleterious> I have a Picasso trigger fish, an algae blenny, and a flame angelfish. In the picture that I am sending there are two tunicates the unknown clam like thing is behind the tunicates. I really appreciate the help. Thanks. <This life is indicative of good care on your part... as well as initial high quality of your live rock. I would take care to not change much of anything in your maintenance, operation routine. Cheers, Bob Fenner>

Liverock Hitchhiker: Bivalve – 10/8/08 Hey guys, <Hi there> I love your site and have been reading it whenever I get the chance. <Super!> When looking through my live rock for the past month or so, I noticed that when I moved passed the lower part of my LR, something would move (it would retract). I have a JBJ NC24 and my parameters are great, but the nitrates are a little higher than I would like them (20ppm). <Yep, you definitely want to keep those below 20ppm. For more information, please see WWM, starting here: http://www.wetwebmedia.com/nitratesmar.htm > My tank is in the process of becoming a FOWLR and I have approximately 40 pounds of LR. I have an attached image of what is in question, I was originally only able to see the front of it and it looked like a flower bud; but after turning over the live rock that it is attached to, I noticed that it resembled an oyster. <It’s definitely a neat little bivalve of some sort. I’m sorry I can’t be more specific, but I’d need to see photos of the entire shell in order to narrow things down. For more information regarding bivalves, please see the following link (as well as the related links at the top of the page): http://www.wetwebmedia.com/bivalvia.htm > I have an algae blenny and a snowflake eel in the tank and they both seem to be doing great =) The blenny in particular gets fatter every day =| I just wanted to make sure, after finding out what this is, that it poses no harm to my inhabitants <None whatsoever> and if it is beneficial; should I consider feeding him anything special? <You could try one of the foods available for filter-feeding organisms, (like DT’s Phytoplankton) but be careful. Adding too much (of any food) can lead to problems – excess nutrients, nitrates, algae, etc. Please see this link for more information regarding bivalve feeding: http://www.wetwebmedia.com/bivfdgfaqs.htm > Thanks for the help guys, I appreciate it! <You’re very welcome! Take care, -Lynn>

strange clam-like object on live rock -08/05/08 I have a piece of Fiji live rock that has a strange clam-looking thing attached to the inside of a hole in the rock. It is usually partially open, but when you slightly bump it with something it clamps tight against the rock. I have attached four pictures...3 of it open and 1 of it closed. <Hmm, it's hard to tell from the photos, but they look like hitch-hiker oysters/bivalves or possibly tunicates. Please browse the following links (and their associated ID/FAQs pages): http://www.wetwebmedia.com/bividfaqs.htm http://www.wetwebmedia.com/invertidfaqs.htm> I have circled it with an orange circle. I was curious if you know what it is and if it is harmful to my other tank inhabitants. <Seems highly improbable that they're harmful... likely just harmless common hitchhikers.> I have a Clarkii clownfish and a Sebae anemone in with it. <Best, Sara M.>

Is a bivalve. RMF

Live Rock Hitchhikers!  7/18/08
Hello Crew,
I am a somewhat experienced saltwater enthusiast, having about 1 year of experience with a 55 reef setup. This year was spent with at least 5-10 hours per week spent reading and researching throughout the entire year.. so it's more than just a 'casual' "hey let's throw some fish and corals in a tank" kind of experience... Anyway...
I just started a Nano tank, for the "challenge" of it. After patiently waiting until the water parameters were stable, I bought myself a nice 3 lb piece of live rock at the LFS. After a few hours, I was looking at the tank and making some observations, and I saw a few neat creatures that I had not seen at the store: a smaller feather duster, some random smaller zoanthid type polyps (hopefully not aiptasia, but they have a deep body, so I'm thinking they're not)
And I thought that was all really neat. However, I was looking at the back part of the rock, and it looked like something large moved! Turns out, I have some sort of clam that attached to the rock and is covered in beautiful coralline algae and some macroalgae. All the research I've done about clams has been the Crocea and Maxima varieties, but this one has the body shape of a freshwater "eating type" (I hope my descriptions make sense..)
Any ideas on this guy? I have about 3.5 watts per gallon lighting and the tank is only a 10 gallon, so I'm not sure what I'll do with this hitch hiker, besides research of course.
Thanks for the much appreciated help and suggestions/insight.
Eric
<Hello Eric. Bivalves -- clam, oysters, scallops, and mussels -- are very diverse, with literally thousands of species known to science. Most are marine, fairly small, and infaunal, meaning they live in sand, soft rock or sunken wood. So from your description it is virtually impossible to put a name to what you have! But you could start here, and see if anything rings a bell...
http://www.wetwebmedia.com/bivalvia.htm
That said, virtually none will do any harm in an aquarium, so identifying them usually isn't critical. The main problem with bivalves is that the majority are filter feeders (a few are micropredators or deposit feeders) so the bigger species often find it hard going in the largely plankton-free aquarium environment. If they die from starvation, you have a lump of rotting protein there messing up your water quality. But small "hitchhiker" species may well survive, even thrive, without undue fuss. What you're actually learning about is that marine invertebrate diversity is an order of magnitude (at least) greater than freshwater invertebrate diversity. Every piece of living rock will have representatives of at least half a dozen animal phyla, including ones you never see in freshwater, such as the Echinodermata and Sipunculida. So, enjoy your new "pets", go grab a book on marine invertebrates, and learn about the wonders of marine biology! Cheers, Neale.>

What is this on my live rock? 07/07/08 Ok I was moving around my larger live rock getting ready to move it to my new 120 reef aquarium and found 7 of these things on the back part of a rock. It came from a always dark area, and I just wanted to make sure they are ok, and not bad. I thought it might be some kind of mollusk, but was told to ask you. Thanks, Clint & Ashley <Hello Clint & Ashley! Looks like some species of Spondylus (or "thorny oyster") to me. These are cemented (i.e., non-motile) scallops. Spondylus have a scallop-like build, but one valve is cemented to the rock and both valves bear spoon-like projections that trap algae and sponges and help to camouflage the animal. Could possibly be Chama spp. though; a similar organism known as the "jewel box oyster" though if I recall correctly it is not a member of the oyster/scallop order Pterioida but some sort of Veneroida. Chama spp. can be recognised by the very deep valve cemented to the rock with a small moveable lid-like valve on top (hence "jewel box"). I remember seeing one of these in a reef tank my father had at home during the 1980s. Seemed to be very hardy and lasted for years without any specific care, though I don't offer that as expert advice on maintenance! Cheers, Neale.>

Good guess/resp. RMF

Bivalve Identification... sans pix  04/11/2008
Hello Crew!
<<Hello John, Andrew today>>
I apologize in advance for not having a picture to attach (I could not get one clear enough to make it useful). I am curious if you can help me with a bivalve ID. I have noticed over the past few months a few (they appear to be multiplying) of these guys in my tank attached to the rock work and most recently the tubes of my pipe organ. They have white shells, similar to an oyster in shape, with what look like thorny, hard protrusions all around the mantle of the shell. The interior appears to be white as well. They are all small, being around a half inch in size. Sorry to be so sparse but I am not sure what other information might be of assistance. They close quite rapidly when touched and appear to be fairing well in the tank since I am noticing more of them.
<<I agree, it does sound very much like a Bivalve, many that it could possibly be from your description. Please read, peruse of the following webpage, including linked articles and FAQ's, see if you can spot which you do possess.
http://www.wetwebmedia.com/bivalvia.htm >>
Thanks for any assistance. John
<<Sorry to be vague John, however, without a photo, it makes this too general to answer. Regards. A Nixon>>

Bivalve Hitchhiker, General Info - 02/07/2007
<Greetings!  Mich with you tonight!>
Hi - I'm wondering if you can help me ID this hitchhiker.
<Definitely a bivalve, difficult to say much beyond that.>  
It appeared about a week ago - I've had the rock for 5 weeks.  It stays put, but does snap shut and retreat when I get near it with the turkey baster.
<Wouldn't you?>
How did it just appear?
<I'm guessing it was probably there all along, but perhaps overlooked.>
Will it move?
<It is possible, but unlikely.>
Grow?
<Hopefully.>
Do I need to feed it?
<Likely a filter feeder.>
Nothing else in the tank yet except hermits, snails and 1 peppermint shrimp.
Thanks!
<You're welcome!>
Pic is attached.
<Got it!  -Mich>

Bivalve ID - 10/14/06 I've included two additional pics of this clam that may help you in identifying it.  Thanks. John <Unfortunately, those pictures don't shed much light on the mystery. Mollusks are quite diverse, and sometimes it's impossible to ID them properly without taking them apart, which I doubt you want to do. We'll be posting these pictures so perhaps someone else might send us a clue. Cheers, J -- >

LR Hitchhiker - 02/13/2006
Hello! I've been a saltwater hobbyist for just a few months now and couple of months ago bought my tank red kelp on a piece of live rock. Recently I adjusted it to where there was a little bit more of the live rock facing me, and a couple of weeks after I noticed (what from all my Internet research), looks like two fan worms growing from it, and what looks like a clam?
<Have to love those freebies!>
After two months of being unfed can this be true, can it survive and if it is what can I do for it?
<It could in fact be a bivalve of some sort, living off what it can filter from your water. Can also be the remains of what had been a bivalve (more often the case). Try to establish for certain that it is alive before you worry yourself about it (at night with a flashlight is easiest). Most likely, you will only need to maintain optimal water quality, let it filter feed for itself. Look here  http://www.wetwebmedia.com/bivalvia.htm for a possible ID. - Josh>

Mystery Critter ID What's up Crew!<<  Just typing away. >> I found this critter clamped onto my Hammer Coral's skeleton.  It took mucho strength to pry it off.  It opens up split from the middle and sticks out a pinkish tongue-like flesh. << Haven't seen the pic yet, but already sounding like a bivalve mollusk. >> It's pretty alien looking IMO.  I'm attaching two photos top and side views.  Really appreciate if you can help me ID it and let me know if it is predatory towards any of my corals or inverts. << Well it appears to be some sort of Bivalve.  Looks cool.  Unfortunately with about 14,000 species of Bivalves, I don't think I can be much more descriptive.  I'll bet it isn't predatory and is a great addition to your tank.  This type of biodiversity is exactly what you want in a reef tank, so I say keep it.  Please continue to watch it, and if it on a coral let us know.  Otherwise keep it growing (it needs live rock, and that's about it) and please take pictures again.  Looks pretty cool, and I'm sorry I can't identify it. >> Thanks a bunch! Roy <<  Adam Blundell  >>

What is it?
Hello; How are you?
<hungry and sleepy but still happy. Thanks for asking... I hope you are well too:) >
I was wondering if you could help me identify something on my live rock. 
<I can and will or I'll make up something very convincing>
I have a 29 gallon tank, with 25 lbs of live rock. It is hard to describe in words but I will try. Last night, my emerald crab was eating stuff off the top of one of the live rocks. As I watched him move around, he touched the top most part of the rock with his claw. (it is kind of a pointed section on top of the rock.) When he touched this part, it sank down into the rest of the rock. When this happened,
it scared him, and he ran down off the rock. After about a minute the pointed section rose back up to where it was before he touched it. Is this some type of bi-valve such as a clam or oyster. 
<Where is the rock from? If Atlantic, reference the Turkey Wing (Arca zebra) ... quite common>
It just looks like the rest of the rock to me, and I had no idea there was something living there. After searching my tank, I found a couple other places where the rock is moving. (I guess another reason to call it live rock!!!)
<bingo... hand that man a stinky Kewpie doll>
If they are bi-valves, will they survive by adding phyto plankton to the water?
<yes... but bottled phyto must be whisked in a blender before every use to reduce particle size or it is hardly useful. Hmmm... don't read that on all the bottles do you :) Research shows...>
Thanks for all your help (both now and my past questions), Kevin
<best regards, Anthony>

Re: Arca zebra
Thanks Anthony, on the speedy reply.
<my great pleasure>
What you wrote was right along my thinking. 
<are you sure that you just aren't feeling gassy instead?>
These guys really aren't going to like burst of water from a turkey baster. They close up when a shadow passes. 
<exactly>
Not that I blame them.
<yep... the shadow or unnatural and "large" burst of water indicate a potential predator>
I have a degree in biology (wanted to be a marine biologist...sometimes life just doesn't work out) 
<I understand... and Mariah Carrey wanted to be a singer>
so I figured that phytoplankton would be my best bet.
<agreed>
Right now I have a bloom of diatom algae so they are probably ok for now.
<helpful>
Naturally, I'd like to rid myself of the algal bloom and then will have to actually feed them. These guys are pretty cool and I'd hate to lose them, especially since that end will probably wipe out my tank.
<indeed a significant mass to be rotting suddenly>
I plan on adding a refugium to my setup anyway, so I'm glad that you think this will help. 
<very much so with the right plants... do avoid Caulerpa for this purpose at least>
But, in the meantime, I may buy some phyto and blenderize it. I'm looking forward to you being at That Fish Place in Lancaster, PA later this month. Perhaps we'll get any opportunity to chat there.
<Looking forward to it!>
Thanks again, Mike
<with kind regards, Anthony>

Bivalve ID- Turkey Wing- Arca species
To Anthony - what is this?
Howdy Anthony! I've attached a picture of something that is growing near the bottom of one of my live rocks.
<very cool... a Turkey Wing bivalve (Arca species)>
Looks sort of like a furry clam, but is long and skinny, and looks as if the shell had formed around a pencil, near the bottom, then the pencil was taken away. (This is where the red spot is, with the shell forming two "hooks".) Hope the pic is clear enough -
<fine enough>
as the critter is near the bottom of the tank, tis hard to get a good angle without taking the rock out of the tank! Is the pic and description good enough for you to tell me what this is? Does
it need a special diet?
<it is a filter feeder. Variable success in captivity. Would likely do best in a fishless refugium. Occasional feedings with meaty juices (small amount) from thawed foods may help.>
(Or, do I need a better picture? - lol) THANK YOU!
>>-Cathy in Texas <><
<best regards, my friend. Anthony>

Oyster Drill snail? 7/18/04
Hello all, I was reading thru your site (one of my favorite things to do in my spare time :)  and I came across some pictures on this page:  http://www.wetwebmedia.com/swsnailfaq3.htm , the comments state that it is an Oyster Drill (Cymatium aquatile) ..... Well, I have searched, your site and all over, and I am not finding any good information on these creatures.  
<they are not used in the aquarium trade for this very reason (hence the void in literature on their husbandry). Tridacnid clams and numerous other desirable bivalves are in greater favor than drab predatory snails <G>>
The few pictures I could find of living Oyster Drills do not look like the pictures on the above linked page, and the only other pics I could find are of empty shells, which tells me nothing at all about the creature.
<there can be considerable variety in form among members of the same family... even in the same genus>
The reason I am asking is because I have one of these things, it was sold to me as "some kind of conch".  I found the hairy shell and spotted body very attractive, so I bought it.  
<this (buying live animals with unknown needs) combined with neglecting to quarantine new specimens is a recipe for disaster in your tank in the long run (introduction of a pest, predator or disease). Please do resist.>
Now, I am wondering, if it is not a conch, and IS an oyster drill, what can I/should I feed it?   Do I need to buy oysters?  Do they have to be live?  Are there other foods it might accept?  What kind of conditions does it need?  It's been in my tank for nearly two weeks, always moving around and active, but I'm worried that maybe it is starving.  Where can I find more/better information on this creature?  Any help is greatly appreciated!  Barb
<the first step is a correct ID of what you have. Without any picture or description of your snail other than general resemblance, it would be unfair and unrealistic for me to speculate. Ask your retailer for more info about where it came from. They should know or their collector/wholesaler at least will know what waters it was collected from. Then take that info and use it to refine your search among the many shell collecting sites. They are your best option in the absence of extensive ID and husbandry info for aquarium use. Anthony>

Bad decisions... wrong species, right admiration 5/27/04
Well, I'm not sure what sea this cowry comes from. I got it from a friend's tank because I'm an invert lover and I think cowries are really cool. ;] 
<fascinating yes. Do check out our coverage of gastropods in "Reef Invertebrates" by Calfo and Fenner too>
I can give you a basic description and see if you can make
anything of it.
<nearly impossible from a text description. A photo at least would be helpful>
It's about an inch long, the shell is creamy white w/out any visible markings. The mantle is white w/ dark purple circular spots all over it. The foot is white/translucent w/ the outer perimeter being purple/dark magenta colored. I'm not too sure what it eats, maybe algae maybe snails. Who knows? ;] It is nocturnal for sure.
<It never ceases to amaze and disappoint me that people bring pets into their home without knowing what they eat/need to survive>
Thanks for any info you can give. Morgan Mok
ps: Do you know where a person can get electric scallops? ;] 
<they are near impossible to keep for anything that approaches a natural lifespan in captivity... unless you have figured out a way to magically culture bacteria, nanoplankton and other necessary plankters>
Also, do spiny scallops/oysters (can't remember the name) need temperate waters in order to survive? Thanks!
<ughhh... if you are referring to Thorny Oysters... they are near impossible just the same. These azooxanthellate bivalves are some of the most difficult reef invertebrates to keep alive in aquaria. They slowly starve over a period of weeks to months categorically (very few exceptions). Please be a responsible aquarist and avoid these specimens. Read more about why on our free content website, wetwebmedia.com, or our last book if its handy. Anthony>