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FAQs about Giant Clam Selection

Related Articles: Got Tridacna? A beginner's guide to keeping Tridacnid clams by Laurie Smith, Example Chapter from NMA Reef Invertebrates book, on Giant Clams, Tridacnids, A Brief Guide to the Selection and Placement of Tridacnid Clams by Barry Neigut, Tridacnid Health: Pinched Mantle Syndrome in Giant Clams by Dr. David Basti, Deborah Bouchard & Barry Neigut, Bivalves, Mollusks, Lighting Marine Invertebrates

Related FAQs: Tridacnid Identification, Tridacnid Behavior, Tridacnid Compatibility, Tridacnid Systems, Tridacnid Lighting, Tridacnid Placement, Tridacnid Feeding, Tridacnid Disease, Tridacnid Reproduction, Tridacnids 1, Tridacnids 2, Tridacnids 3, Tridacnids 4, Tridacnid Clam BusinessBivalves, Bivalves 2, Lighting Marine Invertebrates,

Tridacna derasa and a Premnas biaculeatus, comp.     1/21/12
Dear Crew
I take this opportunity to thank you immensely for the amount of information that you provide which help me every day in my hobby. This is the first time I need to ask you something as normally I find all the answers I need. Here's the dilemma.
Last Monday 16, I introduced a Tridacna in a unpopulated tank (roughly 700lt. system with 1 Zebrasoma veliferum and 1 Premnas biaculeatus).
Everybody seems happy but, today I noticed quite a strange thing. The clown has exchanged the Tridacna for an anemone and she rubs on the mantel and generally behaving in the same way she would with an anemone.
<Yes; happens>
But the even stranger thing is that the Tridacna seems to have accept her. He would react swiftly closing when anything else swim above him but not with the clown.
<I see>
My question is: is it a good idea to let the clown rubbing and resting on the Tridacna's mantel or in the long run that would damage the clam?
<Likely not a problem as long as the Clown is single here... Were there two, a pair, they might over-nip the mantle, damage the clam>
Thank you in advance for your help.
Kind regards
<And you, Bob Fenner>

Squamosa... Tridacnid sel.  03/11/2008 I have been looking for a 3 inch Squamosa clam for well over a year now and I can't find one. I even managed to get a 3 inch Gigas after about 6 months of searching which is hard in itself, but still no Squammy. I have checked EVERYWHERE (LFS can't get any, and I can't find ANY online store that carries them). No one seem to have any that are under 9 inches. <?> Is there a reason why Squamosa clams seem to be so rare these days? ORA's website says they breed them. I heard that some eco-Nazis <...> were making it hard to get Squamosa clams because of some CITES law, is this true? <Am a fan of this International Convention... now if we could only get rid of the waste that is the militaries of the world...> Lastly, do you know ANYONE who sells 3 inch Squamosa clams (yes, I have talked to Barry many times at clamsdirect and he can't find any). Sorry to ask such a trivial question, but you guys are my LAST RESORT. Thanks. <Just gots to be patient... a matter of supply and demand. The U.S. economy is so beaten to death (along with its reputation), that the limited supply is going to other nations/economies... keep saving. Bob Fenner>

Metal Halide, Shallow Tank, and Clams - 06/12/06 Hello, hope ya'll are having a fine morning. <<Mmm, yes...for a Monday>> Just got back from my bachelor party so I can't complain. <<I see>> Anyway, there is a lot of advice out there as far as the appropriate wattage/mounting depth to correlate with certain tank depths, but I can't seem to find any that fit well enough with my situation. <<Much left to personal opinion/subjective interpretation>> Currently I have a 250W double-ended HQI MH lamp with 14k bulb.  My aquarium is a 40g flat-back hex with a depth of about 20" from top to bottom.  After accounting for substrate and unused space, the greatest depth any of my charges can be possibly kept is 16". <<Okay>> My lamp is mounted approximately 8.5" away from the water surface. <<If your corals are acclimated to this lighting then this is fine.  But considering the wattage of the bulb/depth of the tank you could easily move it up several inches...in my opinion>> With the use of a fan heat is kept within sane values (78 degrees). <<Much to be said for evaporative cooling>> I'm worried though that this might be too much light. <<Depends on what you are trying to keep>> My coral charges seem fine and quite happy with the new arrangement. <<Then likely nothing to worry about>> My T. crocea (which I received shortly after) did expel some zooxanthellae right off even though it was placed in the bottom of the tank, <<More likely due to shipping/handling stress, than lighting>> currently it seems fine (mantle spread, not gaping) and I have had it a week now.  My main concern is for my smaller juvenile T. maxima (w/ darker gold coloration). <<Any Tridacnid species under 2" is problematic (seem to be especially susceptible to shipping stress/problems with acclimation)...best to obtain these clams at 3"-4" in size for the best chance at keeping them alive>> Is my concern misplaced, as these are light loving creatures, or should I consider raising the lamp considering the depth of my tank? <<What is the clam telling you?  If it seems happy and healthy then leave as is.  But I also think raising the light a bit won't "hurt" anything if you should so choose>> The T. maxima seems to be happier on the whole since I have started using a sodium nitrate solution.  It concerns me though that no matter how much I add I still seem to have 0 nitrates. <<Likely used/removed very quickly...be sure to make increases in small increments...and keep a sharp eye out for the start/increased growth of nuisance algae>> Could this solution be taken out by a skimmer or PolyBioMarine's Poly-Filter? <<Yes>> It doesn't seem likely, being a salt, but my knowledge in that area is pretty limited. I'll appreciate any knowledge you wish to pass my way.  If perhaps I have missed this information in your faq, I apologize. <<No worries mate>> Thanks for your help! James Tanis <<Cheers, Eric Russell>>

Interzoo 2006  5/21/06 Hi Bob, <Hello Thomas> here is the clam-man from Germany. I haven't seen you this year in Nuremberg <Not in attendance this time around... Unfortunately. BSV sold (my publisher there) and Diana is no longer distributing Knop in N. America... and our friends by and large don't have the time, nor WWM as much money to sponsor them at this time... And the trip afterward to the Red Sea... too much trouble there> I hope everything is fine... Attached a link from the Interzoo - fair. http://korallenriff.de/29interzoo/index.html it would be nice if you could post it in your website.. <Will definitely do. Danke> If you have any enquiries about SUPER COLOR Clams it would be nice to add my company website in your articles.. www.tropical-live-import.de <Will do as well> My clams are liked very much from AMERICAN  and brazil customers and I think I can get some more customers from your country if people know my company.. All the best THOMAS LAGE <Missing the show, seeing friends there... am out in Hawai'i instead sort-of... Wiedersen. Bob Fenner>

Giant clam stats  12/14/05 Hey Guys, <James> I was reading this report again and thought you might find it interesting. The import data for clams is on page 31 (wild caught vs. farmed). This is from 2001, but I doubt things have changed significantly since then... <... a bunch of data are lacking here... mostly missing. The numbers stated for import/export of fishes for instance... how can twenty some percent more be imported/exported? But/and am still surprised at the (stated) current percentages of wild-collected (versus cultured) tridacnids... These numbers aren't accurate... but... why?> Still chugging along steadily on the book, and have started looking for jobs. Hopefully something will come up soon. Later, j <Hope so. Bob Fenner, who would write a review of this piece (you can see my earlier one on the same outfits "World Trade in Coral", posted on WWM... such reports are useful, but indicative of a lack of diligence on data gathering... to put this euphemistically.>

Tridacnid systems 9/21/05 <Hi Adam J here.> I have a ten-gallon nano with pc lighting. The Lighting is a Coralife 96 watt 50/50 power quad lamp. I was wondering if I could keep any clams under my lighting ? <The lighting is ok, it is the volume of the tank that worries me.> I dose calcium and have a CPR Bak-pak also. Would it be possible if I put the clam at the top of the tank ? <Well the four clams commonly seen in the trade are in the genus Tridacnid, unfortunately 3 of which  (T. Deresa, T. Squamosa, T. Maxima) grow too large for your system. T. Crocea stays small enough but is the most sensitive and most light loving of the group.  You would have to place it in the upper ? of the tank on a rock to which it can attach its byssal foot, replace the light bulb every 6 to 9 months and keep the water chemistry stable, which is not easy in such a small tank.> <Adam J.> Uhh...Clam? 8/2/05 What is the best size to buy a T. Clam for my aquarium. <Hi Steve, if you would be so kind as to give us a little more detail about your aquarium, it would be greatly appreciated. p.s. What are the best lottery numbers to play tonight? - Ali>

Re: Ughh...Clam? 8/2/05 What is the best size to buy a T. Clam for my aquarium. p.s. What are the best lottery numbers to play tonight? - Ali> Hi, <Hi again Steve!> well my tank is a 60 gallon aquarium with a two inch crushed coral sandbed. My filtration is a 10 gallon under the tank refugium with Chaetomorpha 7inch deep sand bed and bout 10 pound of live rock rubble. My lighting is a JBJ 4x65 watts PC lighting Two 10k Bulbs and Two Antic blue bulbs for a total of 260watts. <Unfortunately, your lighting at this point might be a little too weak to keep the clam growing and happy long-term. Please consider upgrading to at least 175watt metal halides. If you are planning on upgrading to halides soon, then a T. derasa, T. hippopus or T. squamosa would be good beginning candidates. For what it's worth, you will be 'okay' keeping the above clams with your current lighting set-up (since it's more than likely less than 24" in height) for a good while, however you should look into the lighting upgrade as soon as possible. Otherwise, just wait until after the upgrade to add one of these awesome animals to your system. Good luck Steve and keep searching/learning on Tridacnid species and husbandry. - Ali> Squamosa or Crocea Hi Bob, <Brian> I am looking at buying a Tridacna Clam. My friend is a clam supplier, and he has a great looking Crocea Clam that is 4.5" that has great reflexes to stimuli and a beautiful mantle. He also has a 5" Squamosa that is in great condition also. I was wondering which would be healthier and live longer. <No way to tell> I have Compact Fluorescents (130 watt, 10,000k) in a 54 gal corner reef tank. And is Kent Marine Micro-Vert food enough of a feeding supplement. Calcium and alkalinity are at adequate levels (according to your site) so I figure I'm ready to add one. <Have you read through WWM here: http://www.wetwebmedia.com/ca/cav1i3/Clam_care/Clam_care.htm and the links below? Bob Fenner>

Delbeek, AFM article, T. gigas This is what was in the article. Q.  I love the beauty of giant clams. I really want to add a clam to my 29 gallon tank, which has two small clownfish, a clearer shrimp, a large-polyped stony and many soft corals. Lighting consist of two 65-watt power compacts. I have a Red Sea Prizm Skimmer and a Magnum 250 Hot filter. I use some additives (calcium and coral food). Do I need to add anything else to a clam tank? Are there any other things I need to know about keeping clams? A.  "Several species of giant clams are available to aquarists. Your best bet for success would be a true giant clam (Tridacna gigas). This species does well in captivity and should initially do well in your setup. As it grows, however, it will need more light. You are just on the border for light intensity at 4 1/2 watts per gallon, but keeping this species should be within your system's capacity. At the same time, you will need to move the clam to a larger tank as it grows and grow it will, very rapidly, provided the water parameters are adequate." Now he does go on to say more regarding light and water chemistry. : )  Guess to each their own but I would never suggest a Tridacna gigas in a 29 gallon that seem to have a lot of animals in it so far. JMO. <Doggone it, I thought I had Charles email to ask him re. Can't find on MSN addy list> Nice article <G> http://www.liveaquaria.com/general/general.cfm?general_pagesid=260&ref=3175&subref=AH  <Oh, nice rendition. Bob F> Cheers, Barry www.clamsdirect.com  

Where to buy Gigas clams - 2/3/04  Where can I buy the gigas clam from? <try Barry at www.clamsdirect.com. If he doesn't have it, ask him to pick one up for you. He is a great guy and let him know that wetwebmedia.com sent ya> An internet site, I mean. That sells to hobbyists. <Have fun ~Paul> Thanks, Adam

Colored squamosas Hi Robert: <Steven Pro this evening.> I got your contact info off wetwebfotos.com. Do you know where I could locate any colored squamosas? <Do check out the links page on www.WetWebMedia.com, this is the original information website. WWF is moving towards the selling of images.> I am looking for blue, green, or purple. <Do be aware that certain species only come in some colors. Squamosas are generally not the brilliant colors of Maxima's and Crocea's.> Thanks, Kris Duggan of BerlinMethod.com <Good luck in your search. -Steven Pro>

Tridacnid clam Hi Bob,  <Anthony Calfo in your service> I have a really good relationship with my LFS.  <excellent! a blessing that not all aquarists enjoy> Due to this I am able to order some unusual items, and can pick them up on delivery from the suppliers, before they even enter their tanks. For this reason I sometimes have to rely on them for quality, and it works out to be beneficial 99% of the time. However about 3 1/2 months ago I asked for them to get some Tridacnid clams, and gave my list of preference. When I arrived they had hand picked a blue Maxima or derasa (my guess I was too excited to ask) for me still in it's bag and difficult to visualize.  <T. maxima it is> When I got home it unfortunately had some brown areas along both sides of the mantle (see picture enclosed).  <not unfortunate... perfectly natural and rather common pigmentation> I thought it was just due to being under poor lights and it would recover.  <will not change my friend> I have had it for over thee months in my 125g reef. It is within 2 feet of the lights which are 2-140 actinic VHO for 8 hrs/day and directly under one of three 175 cheapie 55K Venture MH for 4 hrs/day. I replaced the MH. about 6 weeks ago as it was slightly yellow, the new one is much whiter. Is this just some normal marking or am I in for trouble.  <relax and enjoy this beauty... a nice specimen> The clam is always extended and closes very fast when a fish swims too close.  <very good responses...healthy> Any ideas would be appreciated.  <tridacnids are graded by color on export and few of the "cover girl" blue seen in books and magazines make it to the USA. Some Germans and many more Japanese aquarists are willing to pay a much higher dollar for select ultra blue clams than American aquarists. So... we do get some very nice clams... but most/many have variable pigmentation. Your specimen is very nice overall and likely a better deal at under $100 compared to the $300-600 USD needed to get a hand picked (ultra grade) pure blue specimen> Thanks Larry
<best regards, Anthony>
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