TridacnidFAQ

FAQs about Giant Clams, family Tridacnidae 1

A bunch of two inch across Tridacna maxima's in WSI, Fiji.

Follow up to Squamosa - 4/3/03 Hi there WWM Crew... <Hi there. Paul here for a few> Well hello to you Paul. <Back again eh?> I hope you are feeling better today. <Not really> Nothing worse than a springtime cold! <agreed> I have a question regarding the well being of my new T. Squamosa. <OK. Go for it> Is it normal for them to gape for the first few days following acclimation? <Well, in my experience they can "gape" anytime and usually recover. You just never know though. If I remember though it seems to me that Squamosa kinda "gape" anyway.> One can find tons of pictures of Maxima, Crocea, Derasa etc. online. A simple Google search results in only a dozen Squamosa. Most looked like they had larger inhalants but I couldn't tell and couldn't settle until I got feedback from others. I owe it to the shellfish! Thanks for your take on this. <You're welcome> The lil guy was delivered Tuesday and was acclimated over a period of an hour plus. <Well, nice but did he go into an acclimation tank? In any event sounds fine> I ensured that I added some tank water, via a turkey baster, over and over until the container was full. <very well> I then dumped half and did the process over again. After more than an hour, I finally placed him on a piece of empty clam shell just under the substrate for him to become accustomed to his new environs. <Very good. Lights off?> Yes, lights off. As it was, the shipment arrived early, before my photo period. He had hours to adjust before the actinics came on. <Very good> Other than a troublesome wider inhalant, it seems okay. Color is good and mantle expansion seems normal for a newbie. <Sounds about right> The packaging from the seller was wonderful. <Who is the seller if you don't mind me asking?> Oh I don't mind. This guy was wonderful. He and I spoke at great lengths about his clams, my reef and the compatibility of the specimen - down to the appropriate species & size. He held my Squamosa for me until Monday so that it would not ship over a weekend ( I was busy at a Boston Reefers meeting). He followed up with email and again, packaged the clam with great care. I purchased the clam from Just Phish ( http://www.justphish.com/) in CT. JP knows customer service! I will be a return customer. <Cool. He may now have some new customers.> Many air-filled bags of insulation surrounded the live specimen bag. <Cool> There was 2 inch foam lining the box and two heating pads therein. <Good> The water temp was not all that cold, considering it is New England. <What does that mean?> The temperature of the water was not by all means tropical, but was lukewarm on delivery. As it happens, it was quite cold at the beginning of this week. Typical New England Spring.. one day 70F the next, SNOW!! Yikes. Makes my love for California grow even stronger. Some of the gaping may be from the stress of the colder water. That was some time ago now, right? Like a week or so? So I would think he should start coming around soon if not already> I waited at the door all morning for delivery and acclimated it right away. <Very responsible> It was en route for a short period of time (Next state overnight - FedEx) <Still could be a lot of handling between seller and buyer> The reason I chose Squamosa is that I have power compacts. <Ahhh, good choice then> Everyone I speak with says that my 6w/per gallon should be sufficient. <Definitely> I've read the book "Giant Clams" and it too says that Squamosa would be my choice. <Very good. Glad to hear you on board as a Conscientious Marine Aquarist> I was planning leaving him on the substrate, but your opinion on this is appreciated as well. <I would leave him there for about a week minimum. Then slowly start moving him toward his final resting place. In the wild though, these guys are usually found on the substrate. So he may be fine where he is. If he continues to gape though I would definitely hold off on moving him anywhere. Clams have been known to crash and die in about 12-24 hour period, so keep an eye on him. Oh yeah, definitely let the seller know he came to you in this "gaping" condition. From the picture though he looks pretty good!> The clam looks a little happier today. It's mantle has extended just a bit more. His siphon no longer remains open all the time, but is wide from time to time. <Keep an eye on 'em> I guess it's just a "Squamosa" thing! :) So, again, regarding placement. My bulb to substrate measurement is 14 inches. I have 2X55 watt PC's (hmm okay 5.5 watts not 6). Do you think I should leave him in the sand? <If light can get to him un-impeded (read not blocked by Caulerpa or coral then I would start him there for now. Ask Justin of JustPhish or Barry of ClamsDirect but I think he will be fine there. The Squamosas I came across in Palau all seemed to be about 50 to 60 feet on from the surface if I remember correctly. The Croceas and Maximas seemed to be in very very shallow water of anywhere from 1 foot from the surface to about 20.> I may just be paranoid. Others have told me that Squamosa have larger siphons as compared to other Tridacnas. <True> I'm used to seeing Maximas which rarely "open wide". <Also true. Healthy ones anyway> I've attached a picture for your viewing. <Looks good> You can email me direct if this is not FAQ worthy. Definitely FAQ worthy. Did you get a chance to read our FAQs? Lots of good info there. you can always contact Barry Neigut at ClamsDirect.com as he has quite a good amount of experience in the various hobby clams.> I print ALL of your FAQ's and have them in a volume of binders in my home. I have FW, SW and a Koi pond. You folks are a priceless source of information. <A big thanks and tell everyone you can. Even those who may not need the help> Thanks again. Take some Zinc! ;) <Thanks for the reply to my questions. Keep me updated as to his health.> <D>

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>

I Have a Question About a Clam Hi Bob or whoever is taking your place if your not there; <Steven Pro right now.> I've never had a clam before but I'm curious about something I saw on all the clams I have been looking at in the local stores. I believe based on research that these clams are Tridacna derasa. I understand that each has its "mouth" but I'm curious because most of them seem to have a split on the other side of the clam. Is this normal? <Yes, clams have both an inhalant siphon and an exhalent siphon.> Are these clams in distress? <Nope> Do they all get this split? <Yes, what goes in must come out.> Are they forming another mouth? <No> Are these specimens to get or to avoid? <There are other factors to consider. Daniel Knop has written an excellent book, "Giant Clams". Please pick up a copy for your education prior to purchasing any clams.> Thanks, Mac <You are welcome. -Steven Pro>

Quarantine Clams Good morning/evening Steven, <Good afternoon.> If I was only to keep one clam, would that reduce the need for quarantine? <Reduce but not eliminate. Always best to follow good husbandry practices.> Does this creature carry organisms which may also be dangerous for fish/corals? <Possible infectious agents in the shipping water.> Having read quite a bit about clams/care/diseases and predators on your site and others, how would I know if some predator snail/worms which are not commonly visible (remain hidden in attached rock) were present, short of seeing the clam die? <See if you cannot find Daniel Knop's excellent book "Giant Clams". He has written an extensive section on identifying and treating various "diseases" of clams. -Steven Pro>

What Needs Quarantined? Greetings, Do you need to quarantine a maxima clam? <Best to quarantine anything.> If so, why and for how long? <Generally two weeks minimum with one month being best. Clams sometimes carry parasitic snails that can attack and kill clams in the confines of aquariums.> How do you get around the need for metal halides in a quarantine situation? <You really can't. Again, it is a matter of investment. Clams are not cheap and if you have several, bring in a new one that is infected, and then lose all your clams, you will wish you had quarantined. It is actually a quite frequent story that you hear.> Do you need to quarantine soft/hard corals? <Yes, and live rock too.> Many thanks, Michael <You are welcome. -Steven Pro>

Re: Harlequin Tusk & Bird Wrasse in Reef? Hi Anthony, Thank you so much for advising me on those beauties. <always welcome, my friend> Well the HT and BW I saw in the shop is less than 7 inches long. <which sounds like "up to seven inches" to me...heehee. They typically come in large (5-6 inches) and sure don't stop growing from there> Are they OK with the tank? Latest I heard my clams could be in danger with these guys. Is it true? Don't want my expensive clams to die. <clams are portable and can be smashed against the rocks easily. Although not preferred fare... I cannot convey strongly enough how large wrasse species do not belong in a reef. You need a FOWLR tank for these bulls> ps. Was wondering how you guys run your service? I mean do you do it on voluntarily basis answering idiot question like mine or is it subsidized by something else. You guys are wonderfully incredible in assisting people out there with marine issues and I think we should do something back. <thanks kindly... all volunteer work. Bob started this great site out of his kindness and empathy for the industry and aquarists.. as it grows, he enlists the help of friends like us. Best regards to you and all, Anthony Calfo>

Stressed Out Clams? Dear WWM Crew, Gentlemen, how are you? <very well with thanks!> I need your professional advice once more; I hope you don't mind as I truly appreciate all your efforts/inputs to improve this hobby. <thanks again... but it is not entirely altruistic: Bob pays us handsomely in chocolate malt balls> I have a few questions regarding my recently purchased squamosa clam and maxima clam. First, let me preface by giving you the conditions of my 90 gallon reef tank: lightning--powered by 2x-175 watt 10,000K metal halides and 130 watts of actinic PC, and water parameters--pH @ 8.3, carbonate hardness @ 10.5 dKH, salinity @ 1.025, calcium @ 400ppm, temperature is constant @ 78 degree, magnesium @ 1300ppm, ammonia @ 0ppm, nitrite @ 0ppm, and nitrates @ 2ppm. Fishes included are: yellow and purple tangs, and 3 flame wrasses. The two clams were purchased 3 days ago and they are both about 3.5 inches. They are placed at the bottom being acclimated to my lightning system. <excellent... that was my first question in mind... Good move> I plan to move the maxima clam towards the middle of the tank at the end of this week and leave the squamosa clam at the bottom. Would this be a wise decision? <because of adult sizes and likely light requirements, I would agree that this is reasonable> My concern with both of these clams is the wide opening of their incurrent siphon. It is more pronounce with the squamosa than the maxima and this occurrence only happens when the metal halides are on. <many theorizes for this...not all bad. Have you read Daniel Knop's Giant Clams book? Excellent!!!> When the metal halides are off and only the actinic PCs are on or the lights are completely off, the incurrent siphon is completely closed. Is this normal behavior? <the predictability of it is reassuring but categorically it may not happen with all> Or should I be concern with predation, sickness, and/or accumulated stress from shipping? <do examine closely (and periodically 4-6 times yearly or better) for tiny Pyramidellid snails> I performed the shading test, and the maxima is very responsive to blockage of light and the squamosa is less responsive. < an unreliable test. Some like T. gigas hardly respond at all> This has led me to wonder about the correlation between the squamosa having a wider incurrent siphon opening and its slower response rate to the shading test as not being in good health. <not necessarily> I have also checked for predation with a flashlight at night and I did not see any snails on the mantles. <excellent> I feed DT's twice a week. <hmmm... do read in Knop's book about feeding protocols and foodstuffs. Also, review past FAQs and archives on how best to feed such phytoplankton supplements unless you are already using a blender> Is there anything I do to help them? Any comments and/or input is greatly appreciated. <unfortunately the clam is not exhibiting any symptom that we may fairly act upon. Your system is very fine, and acclimation procedures quite considerate. It may simply be acclimation/adaptation or even nothing at all. Do not be attempted to move the clams at all for at least 2 weeks. Observe their behavior and follow up here if necessary. I suspect at the end of two weeks there will be no new news <wink> and all will be fine. Best regards, Anthony> Thank you, Dan

Is my clam doomed I have recently acquired a 2" derasa clam. He was 10" under 200 watts of SmartLight. Last night he jumped down a step on my live rock, but he left behind some white tissue still attached to the rock above (byssal (sp) tissue?). <correct> Is there anything I can do or anything I should look for Thanks Jeremy PS other than this he appears to be in good health <no worries at all... clams commonly abort old byssal tissue. It is generate new at the new point of attachment. Freshly imported/disturbed clams will often do this. Probably just fine. Make sure it attaches soon for its own good (protection of byssal port from crabs, worms, etc. Anthony>

Light on Clam would 200 watts of CSL SmartLight be enough light for a small clam (maxima) on a 55 Gal tank??? Thanks Jeremy <yes...very fine, but do be sure to keep clam within top 1/3 of tank for best success. Clams really do enjoy bright light, and fluorescents do not penetrate deeply in water. Kindly, Anthony>

Squamosa clams dancing the Irish jig <Anthony Calfo preparing myself for the upcoming trip to Germany...eating sausage casseroles, sausage omelets, sausage pie and sausage milkshakes...with a sauerkraut garnish. All washed down with warm dark beer. Nobody light a match!> Hi again! <Salute> I have 2 squamosa clams that just will not keep still. <when you've got a good song in your head, it is hard to resist finding a groove... cut them some slack, my friend> I place them on a flat surface and the next morning they are on there side or on the sea floor, I have more than enough lighting ( I am the guy who is making lava in his tank) <Ahhh, yes... I remember... 400 watt halides over 2" of water... making steam. How you 'doing?> my T. Maximas are all doing fine and staying put. <like deer in 400 watt headlights...heehee. I'm just joking of course (thanks for being a great sport...and target <wink>). High intensity lighting is very appropriate for T. crocea and T. maxima clams, in particular> I don't understand there fully expanded taking in all the rays I give them but they keep moving. Someone said to me you better move them from that spot cause they aren't happy. <nope... I disagree. As much as I enjoy teasing folks with big watt MH on aquaria less than 30"... too much light is not your problem in this case. I had the pleasure of having two XL squamosa clams (12-16") spawn in my greenhouse. They were in full sun with barely two inches of water above them and supplemented with a 400 watt halide (ahem)> Well I have moved them to other areas of my tank and I still get the same results. <Aiiieeee! A good way to stress/kill symbiotic animals. Never move photosynthetic reef inverts even twice in one week through different light intensities...especially when new (having been imported and run through 2-5 light intensities through the 1-2 week chain of custody on import). Very stressful for the animal to compensate for especially if their fatty storage is low.> Currently now I have one in the sand and the other on a ledge where I have a blue Staghorn coral. so, tell me what can I do just leave them be??? <best if placed on a piece of rock to protect byssal port from predation by segmented worms, crabs and especially (although not foolproof) Pyramidellid snails. The chap on the sand can simply have a flat rock placed under it and buried in the sand. I'd actually place both clams on a flat rock in the sand. This will leave room for maximum growth for this species the third largest Tridacna species. Reaching 18" in well under ten years. Plan for this kind of growth. They are moving because they simply want to be lodged in place in case of a storm (that will never come in your tank)... kind of. Once they are where you would like them to reside, place a temporary campfire of rock rubble around them to hold them in place. After a few weeks of being unable to move or tumble, they will set byssal tissue down to the rock under them... after which you can remove the rubble campfire and better enjoy them aesthetically. Kindly, Anthony Calfo> Tired of moving......... Walter

Wise with Seahorses, invertebrates, Tridacnids Hey, <Whassuuuup?> Thank you for the quick response on my questions about my proposed mini-reef setup. <quite welcome> I have decided against getting sea horses after being advised that it would be best for a seahorse to be kept in a tank which is at least 20 inches tall. > So I guess I will now be going with a fish or two, some corals and possibly a clam. Could you name some corals which would do well in my 110 watts of PC light (over a 20 gallon) and that could be kept by a beginner to keeping corals? Also, will any of the species of clams be ok or do you have a species that you would recommend? <with that much good light over a twenty gallon, you can keep more species seen in the trade than not. Stick with mostly soft corals (finger and crown/mushroom leathers) and Zoantharians (button polyps and mushroom anemones)... they're are hardy and colorful. Avoid stony corals as a beginner (LPS and SPS). The hardiest clams are Hippopus species, T. derasa and T. squamosa. Other blue clams will need bright light in shallow water> Thank You, Jonathan Pac <very welcome>

Giant T. deresa clam Hi, <howdy do?> I was wondering if it would be safe to put a giant deresa clam in my 240 gallon system, with my show size emperor angel? Or will he start munching on the clam? < not recommended unless you have immediate recourse for the clam. I would suggest that you do not try it. Anthony Calfo> Linstun

Lighting for T. maxima Hi Bob <Hello. You got Steven this morning, doing my little part.> Hope all is well for you these days. I have read over your site on lighting for clams and I am still a little confused on what lighting I can use to successfully keep T. maxima. My tank is a 120gal 4x2x2FT. It is a very successful Berlin system with 200lbs of Fiji live rock and about 150lbs of Fiji live sand. It has all of the usual SPS, LPS, and soft corals and inverts. My sand bed is 4inches deep. My lighting is a CSL 48INCH halide hood. The halides are 2 250watt 10K's with 2 65watt pc actinics. Will I be able to keep these animals thriving and well with this amount of lighting? <That seems like plenty of light for what is really just 20" deep at over 5 watts per gallon.> Thanks in advance. Take care. <You are welcome. You too, Steven Pro.>

Building a Dream Tank Hello again Steve, Thank you for the quick reply! You asked for more info about the tank in the picture I sent. I will direct you to the web site I found it on http://www.cpfarms.com <The link does not seem to work or perhaps the site is down for some reason.> They had a members contest and that tank won third place. I don't know if it is still posted on their page. These are tanks for Japan. I used my translator and the best info I could gather was the following. It was a standard 90 gallon tank. Berlin style. 250w.HQI with another lighting set up I was completely unfamiliar with. I'm sorry I can't understand the translation. It had been up for a year and a half. The owner Chita Satoshi commented that the only major problems were being able to get the Clams to stay amongst the rock work. <T. crocea are comfortable amongst rocks, but maximas prefer to be on the sand. Try to get Daniel Knop's excellent book "Giant Clams".> I am only assuming that their is use of a calcium reactor, though there was no mention of one. <A good idea to have one> I know that is not much to go on. I was hoping that just looking at the corals themselves you could let me know if (using the correct equipment) it could be, not copied, but matched. <Yes, if looks very doable. Some suggestions. 90 gal. tank with built in overflows, preferable over siphon hang-on units Sump with high quality skimmer; Euro-Reef, Tunze, Aqua-C, etc. Return pump(s) rated at 900 gph or greater (check that overflows can handle this) 2 175 watt MH's with 10,000K Aqualine Buschke lamps Supplemental actinics supplied by 2 48" VHO's or 2 36" PC's Water purification unit (RO, DI, or Kold-Sterile) Calcium Reactor... 4-6" Deep Sand Bed... Small quarantine tank for new additions Most importantly, a good source for livestock> Thanks again. Josie

Lighting requirements, selections Hi Bob, I would like to add a clam or two as well as SPS corals to my 50 gallon reef. I don't know if my lighting is good enough. I have two AGA fixtures 110 watts each of PC's. One of the fixtures is 110 watts of actinic lighting, the other is 110 watts of 9700K daylight for a total of 220 watts. Is this strong enough lighting ? Can the clams be placed on the bottom of the tank in the sand bed ? <Should be okay... would be better to have more "white light" wattage... but no worries. The Tridacnids will just grow more slowly, not be as open, colorful. Bob Fenner> Thanks for your help, Mario

Clams Hello my name is Christopher I would like to know were I could find information on breeding Tridacnid clams thanks for your help <A few places on the net. Try the Breeder's Registry first. Link can be found on WWM: http://www.wetwebmedia.com/links.htm Bob Fenner>

Zero nitrates w/ refugium vs. giant clam Hello Mr. Fenner- I have read all the refugium notes/FAQs and I'm sold on one. For my future 92 corner tank I will use a 20 gal hex for the sump and one for the refugium (have an odd-shaped stand). From my limited (but growing---thanks!) knowledge, I understand that giant clams actually like some nitrates. <This is so... to a degree.> I plan to start as basically a FO system, but I want to set it up as properly as possible w/ long term reef results in mind. So, what is your "official" opinion on clam + skimmer + Miracle Mud refugium? Thank You! Erik Nelson <Of all timely notes... picked up Leng Sy yesterday on the way to going to Hollywood, giving a pitch to the combined L.A. and Orange County marine clubs... and Leng and I went over and over re skimmers, his mud product... We kind of agree that "skimming has its place" and in general, after some time, balancing (a few months typically), a not-too efficient skimmer can/should be cycled on/off (day intervals) to allow production of planktonic organisms, in the face of a dearth of removable materials... in most systems. Bob Fenner>

Derasa Clam problem.. Hello again, I am writing to you this time about one my Derasa Clams. I have had them both over 1 month and they have been looking fine. Both have been placed on the substrate in the middle of the tank. Today, I noticed that this one in particular, had receded it mantel way back into its shell and the mantle has started to separate from the shell. It does open and close occasionally. The other clam is doing well. I am using 96W PC lights from Custom SeaLife (8800k daylight and 6700k actinic). I have plenty of water movement 1 Rio 800, 2 Rio 180 and water moment from an AquaClear 300 and HOT magnum (both about 300g.p.h.). Water levels are temp = 76.6, PH = 8.1, Ammonia and Nitrite =0, nitrate = 2.2, dKH = 9.14, Calcium = 490, Phosphate = 0. <Mmm, your calcium is a bit high...> All of my corals Euphyllia sp., leathers and plate corals are thriving. I have read through the FAQ's section on www.wetwebmedia.com <http://www.wetwebmedia.com/> and did not see any similar instances of this happening. Am I losing a clam or is there something I can do to save him?? <Even after a month, this specimen may simply be "settling in"... Do take a close look (especially at night with a flashlight) to ascertain whether "somebody" is bothering this clam... worms, snails... can be trouble. Bob Fenner> Regards, Keith Broadbent

Re: Derasa Clam problem.. Do you think he may not be getting enough light and to try moving him up higher on the reef?? <Hmm, possibly... worth trying. Bob Fenner> Regards, Keith Broadbent

Clams Hi Bob! How's it going? I just had a few quick questions for you. I am considering buying a cultured crocea or derasa clam. I have a 55 gal aquarium, 18" deep, w/2 48" VHO's (03 and 50/50) Is this enough light to sustain a clam? <Mmm, not really... need, could use about twice this luminosity> Could I put it on the bottom, or would it be better to find a flat surface about halfway up? <Near the very surface... Bob Fenner> Thanks in advance. Erin

Clams Hi Bob, I read the e-mail from the person with the clam-swallowed clownfish with interest . . . and then it got me thinking. Would you consider your average giant claim to be a fish predator to worry about? <No... close very slowly compared to most livestock... and generally not "all the way"> Or would you classify this more as a low I.Q. / careless fish story -- the theory of natural selection at work, if you will. <Well put. Wish I had written thus. Bob Fenner> Dale.

Clownfish swallowed by Clam Alright. I know. I should have gotten an anemone. <Mmm, really?> But I was busy setting up the 75 gal tank and ... Anyway, My Gold stripped Maroon clownfish thought that the clam was an anemone. I had noticed yesterday that he was really "chumming" up to the clam (more than normal). I got home last night and the damsel and all the other fish look disturbed (usual first sign that something is wrong). I then looked for the clownfish and lined up the usual suspects and interrogated them (well, really I just checked the crabs and the green brittle star [he's still smaller them all of the fish- but he is going in the refugium]). But there is not a body and the skimmer looks about normal. Ok - check the tank again, check every small hole. check again (and again). I still could not find Mr.. wiggles (er.. the clownfish). So I think the only place he could be is in the clam. I debate this for a half an hour and finally think that it just can't happen. This morning I wake up and feed the fish, when I see this maroon fin sticking out of the clam. (Oh yeah, that's what I want to see). Well there it is. The clam ate my clownfish. But no, wait. The fin is moving. The fin moved again. So I decided to rescue Mr. wiggles. I pried open the clam (it didn't take a lot of effort) and out comes Mr. wiggles (who will need at least ten years of therapy). In the process, I dislodged the clam from its shell on one side. I probed the clam and there was no reaction from it, so I found a place that would close the shell without using too much force. My question is: Is there any hope for the clam? <What a delightful write-up! Yes to hope, recovery... Bob Fenner>

Clam questions Bob, Thanks for you response. I have some additional questions though, - You mentioned it might be a lack of light, but I didn't think this was the case because the clams didn't overextend their mantle (as described in Knop's Giant Clams book), and they didn't show any bleaching that I would expect. I also tried a variety of placements in the tank - including placing small maximas/Croceas (1") within 4 inches of the surface. <Mmm, the placement is a valid indication, the non-extended mantles, bleaching not necessarily so> Also, the demise is sudden - the clams usually look healthy for 1 month or more, and then die within a week (usually within 5 days). Am I missing something in regard to light? <Not likely if the losses were rapid onset... more likely something amiss with chemistry (mis-supplementation in most cases) or an undiscovered parasite load of consequence (like Pyramidellid snails)> - You asked how I maintain water chem. I use SeaChem's Reef builder and Reef Advantage Calcium. I also use instant ocean salt. (I am in the process of converting one tank to a calcium reactor - Korallin). Is my use of SeaChem's products potentially involved in the demise of my clams? <Doubtful. No other additions?> - You discounted my thoughts on predation. The one thing that keeps pointing me in this direction is that I NEVER loose multiple clams at once. Its always one at a time. And then shortly (within 1-2 wks) after one dies, another one starts to show symptoms. Again, can you expand one why you don't think its predation? <Could be... In accounting for how many specimens lost this is just historically about third, fourth in line as common causes/categories of loss> - Do you have any idea of what the normal survival rates for maxima/crocea clams are when they are purchased from good mail-order firms (FFExpress, and others): <Just guesses... such data are rarely recorded, never shared in the trade> 1) the small ones (1" and under) 2) medium (1 - 3") 3) large (3+ inches) <Hmm, I would state with certainty that "larger ones live longer"... And guess that one inchers on mean/average probably only make it a month, 1-3" probably 2-3 months (most are "killed off"), 3" ones probably 4-6 months... Some folks do keep any/all sizes for years... but most "don't make it"> The reason I ask is I'm trying to get an idea of what constitutes 'Success'. <My friend this is beyond us! "Smiles per hour"? Reproducing? Closing the loop, having tank bred young grow up, in turn producing viable young? A subjective measure, the affective domain... "how you feel"?> I haven't had much luck with long term clam survival (except for my large and indestructible derasa), but from what I've seen, the LFS's don't seem to have much luck either. <Some sources, lines are decidedly much better than others... Much has to do with how these animals are kept, treated "intermediately" going from almost wild culture facilities through holding/shipping... Need TLC at this crucial junction... intense lighting (likely MH), foods, feeding, addition of biomineral, alkaline materials... Only know of three outfits out of dozens that provide this level of care... their clams are healthier, on "average" live longer/better> - You mentioned phosphates (and Knop indicates nitrates are needed) for clam health. <Yes, actually for all life on this planet.> My kits have always registered 0 Phos/nitrate. Should I be 'injecting' phosphates/nitrates into my tank (gosh - this is tough to swallow, given the effort I went to eliminate them). <Mmm, regularly exogenous (outside, provided) feeding of your livestock should present enough of these... do you have too vigorous "other" transport mechanisms? Like chemical filtration, too much macro-algal growth...?> I have red-sea Berlin classic skimmers running on both 75 gal tanks, with 100+ lbs of Fiji LR and planted/lit sumps. <Might try trimming back the macrophytes in the sump> This combo seems to bring nitrates/phosphates to immeasurable levels, at least with my test kits (nitrates under 2.5 ppm, phosphates under 0.05 mg/l). I'm sure there are some levels of nitrates/phosphates though, because the macro algae - Caulerpa - in my sump grows well. - any other suggestions on what I could try to increase my survival rates, or what could be the cause? Thanks again - and apologies for the long note. <We will be discussing this... nature further. Bob Fenner>

Clam question Bob, I'm back with additional questions. I have 2 75 gallon tanks both with PC (4 55 watt -7100/6700K on one tank and 4 65 watt - 8800K/7100K on the other tank). I'm having problems keeping clams for long periods of time. (Nitrates, nitrites, ammonia, phosphates are 0, ph 7.9 - 8.4, Calcium is 400-450, Alk 9-10, salinity 1.023 - 1.024, oxygen is at saturation, temp 78 - 80). <Mmm, could be a few things... including a need for more light (or moving the animals up in the water column), foods/feeding of the clams, a lack of phosphate... got to have some> I've had one derasa clam (4 in shell) that has survived for 2 years now and has always looked like it was thriving and continues to do so - its added 1 - 2 inches in shell growth since I purchased it. I've had a maxima (3 in shell) that thrived for about 8 mo.s, and then suddenly died. I've also had several baby maximas (1in) - roughly a dozen - and around another dozen or so small crocea/maximas/squamosa/derasas (2 in) that have also died. Basically, they appear to thrive for several weeks, and then they all appear to become ill and die within 1 week: - initially, they fail to extend their mantle much past the shell edge. - then they start to show 'gaping' on their inlet siphon. (within 1 -2 days) - then (within 1-2 days of the 'gaping') they suddenly die. <How are you modifying your water chemistry? Doesn't sound like predation, parasitism...> Usually their is very little flesh left by this time - my reef hermits will consume what's left within 24 hrs. I suspected the hermits, but they seem to ignore the clams until the very last stage - when its obvious that the clam has died. Also, if I have multiple clams in a tank, they never show illness all at once - its always a one by one demise. I've also tried a variety of positioning of the clams (bottom, middle, top) to no avail. I've suspected a predator, but the shells don't show signs of a boring sponge (or any bore holes from snails). The remaining flesh also appears free of predators. Any ideas what could be causing this - and why my 1 derasa has never shown a day of 'weakness'? <A tougher species, individual for aquarium use> Are small clams inherently more susceptible to illness? <Yes, more> I also had a few additional questions: - are you familiar with the AquaLogic cyclone titanium drop in chillers? <Yes, some> If so, are their titanium coils fairly safe (in terms of poisoning tanks)? <Yes> - What is your opinion on the Tunze skimmers and the ETSS skimmers? <Tunze products are excellent, though pricey. ETSS skimmers are great technology for very large (hundreds of gallons), "messy" systems, in situations where folks don't mind spending the money on high volume pumping. Needle wheel technology is superior to downdraft. My opinions are posted on the www.WetWebMedia.com skimmer sections> The Tunze claims to be completely plankton safe (I've heard the ETSS marketed as plankton friendly). <Mmm, the Tunze much more so> Are these top notch skimmers? <Top notch?... for the types of skimmers they are... Tunze particularly for size, cost of operation are very well designed, engineered, built... ETSS are more garage/chop shop put together> Is their 'plankton' spin true, or just marketing? <For Tunze more true> - The ETSS website claims that skimmer throughput (gals of water/hr) is a very good measure of a skimmer's ability. Is this a good measure to compare different brands of skimmers? <No, ridiculous... what does flow rate have to do with removal of unwanted materials. Removal per kilowatt energy consumed, per pass... these are measures of efficiency. Look at the EuroReef line for a paragon of excellence... their link can be found on WWM. Bob Fenner> Thanks!

Just lost a Derasa and a Maxima Hi Bob, <Yikes, what happened?> I feel so sad that I just lost two / all of my clams, one Derasa and one Maxima. I have had them for 9 months and a year respectively .. both died within a week apart. I first notice something is wrong when they wouldn't open that much, tried to adjust lighting, but the shrinking continued and then both were in some sort of "gaping" position until I removed them. I noticed they both seem to have lost their legs and that it looked very hollow bottom up. <Hmm> I am a little puzzled and very concerned with the clam losses. If you remember, I am in the middle of battling Cyano and looking up my log, I setup a refugium with macro algae and took out the HOT with AC and phosphate sponge 2 weeks ago. Other than that, everything else have remained the same. Do you think they died from poisoning from the macroalgae (there has been no dying though)? <Doubtful> Or is there some sort of a "predator"? <If they were "hollow" inside it may be so... Pyramidellid snails, some polychaete worms can eat Tridacnid clams quickly in numbers> I added the Kent buffer to boast alkalinity over the last 2 weeks, from 6.8 to 11.2 then 12.5 over 2 weeks. <Mmm> My parameters are: 60G reef, Ph 8.0, NO3 2.5, PO4 <0.03, Alk 12, Ca 400, temp 80-82F, 45lbs LR, 1-2inch sand. Livestock: flame angel, yellow tang, damsel, goby, bubble corral, frogspawn, flowerpot, mushrooms, sun corals (all arranged at a distance from one another), cleaner shrimp, Astrea and hermits. Thanks. Brian <There was nothing left of the clams? Very strange, as in disturbing. Bob Fenner>

Clam Questions! Hi Bob, How are you these days! <Fine> I have these weird encounters between my 4.5 inches clam that I bought last week who is moving and getting rid of the poor thing. Anyway! two days after I got the clam he was happy, in fact still is under the metal halide about 9-10 inches below the 175watt MH, lying between 3 rocks. The strange thing I saw was the snail (which I believe a somewhat related or maybe it is a turbo grazer type) (this snail also runs across the algae and suck on them clean), was attached to the clam. I decided to pick the snail and pull him off the side of the clam, man! I had to pull him really hard, which I thought what a good suction! <Yes... good designs...> Today! I went home and saw the snail attached again, I pulled him off and it's even harder to pull this time, but the strange thing I noticed was the hard shell part of the clam had hole as if someone tried to drill a perfect hole. <Perhaps "they" did> I know the darn thing is really hard, and can't imagine the snail would do this kind of thing! I'm afraid that the clam might die from this situation, because a year ago, I used to have 5 of those regular looking (round shape) turbo grazer snail, until I bought this strange looking one which he did the same thing attached to these snails, and died few days later. As a result I have tons of small snails (baby ones). I have 2 theory, 1 good and one bad. Lets start with the good one first, which is he thinks his trying to mate with his own kind! <Nah> 2 his feeding on the clam, but how can that be if the snail feeds on the algae AKA vegetarians type. <Things are not always as they seem... this animal may have a wider food preference than you assume> The mysterious part is how the heck did he put the hole through the hard shell of the clam? <A radula, odontophore... specialized structures like a rasping tongue and muscular apparatus for such boring... and secretions to aid in melting the non-living matrix of the shell... There are several groups of invertebrates with species that do this...> I thought I would go directly to the expert, thank you in advance, hope you have a good one. RL <You as well my friend. I would surely remove this snail. Bob Fenner>

More PC's for deep tank, Tridacnids? Hi Bob Boy I love this site!! I get most of my questions answered without bothering you, it's great. Thank you very much! I just finished checking out the queries on reef lighting. Don't take offence, but I'm still a little confused. <No worries, help me to be more clear, complete...> My tank is a 120gal. and with all of my live sand it is 20inches deep. I want to get some maximas, but don't want to switch to halides. I have CSL 4 96watt PC If I get another hood with 4 more 96watt PC's, can I keep the clams on the bottom, and still keep them happy and healthy? <Yes> I don't want to put them high in the tank like some folks do, just want to keep them in the sand bottom. I hope the 8 96watt PC's will work, halides are too hot to leave them burning while I am not at home, Also the electric bill will be sky high!

Another Lighting Question Hi Bob Sorry to bother you again with another lighting question. My 120gal reef tank, has one set of the 4 96watt PC's on it. If I added another set of the same 4 PC's on it will I be able to keep SPS corals and maxima, and crocea clams healthy and happy? <Should be, yes> The watts per gallon would be 6.4 per gallon. The reason I am asking is that the PC's are much cheaper to run as far as the electricity bill goes. They don't get as hot either , also the bulbs last MUCH longer. The PC's are also much cheaper to purchase. I know that the wattage is there, but I didn't want to purchase anything yet till I found out all of the info I can on this. Your honest opinion will be greatly appreciated. thanks <Yes... and do seek other reliable sources. Bob Fenner>

Maxima Clams, Lighting Hi Bob Just a quick question, I have a 120reef tank , 24 inches deep. I am getting conflicting theories as to keeping maxima clams with the lighting I have. Jerold from flying fish express tells me that I will be able to keep them on the substrate, and that they will be just fine. The fellows at champion lighting tell me that I should keep them about half way up the tank. can you clear this up for me? I really like only the maximas, and the Croceas, but I don't want to purchase them if I can't keep them healthy. thanks and take care.

Clams Hi Bob, I'm considering adding a clam to my reef tank. I'm not sure if I have enough lighting to maintain them properly. I've got a total of 300 watts of VHO lighting, over a 92 gal corner tank (24" deep). Would this suffice if I kept the clam approx. 12" below the bulbs? <Should, though more intensity, CF, MH would be better.> I also have 20 hermit crabs and an emerald crab. Do these pose any threat to the clam? <Some species of hermits can be harmful to Tridacnids, more if hungry... Mithrax rarely> Thanks again and hope all is well, Tony <Do buy, read over the various "Clam Books" before investing my friend. Bob Fenner>

Clams Hello Bob, I have Derasa, Maxima and Ultra Crocea clams, and they seem to be growing and doing fine. Although I notice there not at all as bright and detailed in color as they were the first few months I owned them. Now the colors aren't that brilliant and they look blurred vs. detailed. What could be the cause of this? I have these clams in a 30g reef with two 36in VHO (one blue, one white) that run nine hours a day, and I replace them every 8 months. Iodine 0.04, Calcium 425, alkalinity 3.5 phosphates low and can never get PH above 7.9, (even using buffers daily PH will rise to the 8's, but fall within 15-20min back to 7.9, 7.8). Any information you can give me is greatly appreciated. Thank you, Rob Robcook <Hmm, could be a few things contributing to your Tridacnids lack of apparent color/vigor... Most all to do with the small size/inherent instability of your system... Congratulations are due you for your success with a thirty... as you have found out, it's hard to keep stable and optimized... If it were my clam tank, I would do a few things... For one, I'd increase your lighting... you could easily stand to double the intensity you list... best by adding, switching to compact fluorescents... And I encourage you to add a sump/refugium with live rock, macroalgae and its own lighting, leaving it on continuously or alternating the cycle with your main tank...this will do several things for you and your clams... increasing pH, making water chemistry more stable/optimized... provide more food for their filter feeding... Otherwise, I might well add a vitamin, nutriment solution like Micro-Vit or Selcon to the system... and some small fishes to add their bit as well in the way of "processed nutrients". Bob Fenner>

Critters on Tridacnid clams... Bob, I have a question that I was unable to find in your book. Or any books I my library for that matter. After a recent outbreak of what I think was velvet, I removed all of the fish from my pseudo reef display tank, and put them in quarantine with some medication. The fish seem fine, but have one week of the recommended four left to let the velvet die in the main tank. <A month at the minimum... two if all can stand it... and hope you have availed yourself of raising temperature and lowering spg... mid eighties and 1.018 or so respectively... to reduce virulence, speed the demise of the parasite(s)> I'm still in search of the source of the infection since we have not added a fish to the tank in 3 months, and yes we dip and quarantine all new members of the community! <Maybe the food? Contamination brought in from another system via a net, specimen container...?> The issue is the display tank. It is being over run by critters. Some are nearly shell less snails. "Limpets" or something like that. Others are small fast moving guys that skim across the sand and rocks. I assume they are Mysis shrimp or something like them. I have been "feeding" the two cleaner shrimp and soft corals to keep the biofilter running. <Don't sweat these... very likely innocuous, maybe helpful, and likely transient... especially with the reintroduction of fish livestock> None of the critter sightings bothered us much, we figured they had been there for a while and the fish had been feeding on them, particularly the six-line wrasse, P. Springeri, P. Fridmani, and neon gobies. We just figured the fish would have a feast when they returned to the tank. <Yep> Today, however, we found one of our clams closed up, when I picked it up, about 50 of the shrimp like critters scampered away, and several of the limpets were on the shell. This leads to a chicken and egg question. Is the clam sick and the critters were attracted to the dying clam, or are the critters killing the clam? <Hmm, too much likelihood of the latter to suit me... may be time to expedite the return of your fishes... at least the six-line wrasse.> We have two other clams in the tank, and while they seem to be irritated on occasion, they are open. The rest of the corals & polyps seem fine. I'm sure the fish will have a field day when they return next week, but I wonder if we should do something for the clam? Also, how do coral only tanks survive with all these critters? Are they a problem? Should we be concerned, or just marvel at the diversity of life in the sea? <By exclusion, through lucky mixes of other factors... I wouldn't marvel... I'd replace the wrasse.> On a lighter note, I love our tank so much, that I went and got scuba certified. We are thinking of going to Cozumel. Any suggestions? >> <A great place for new scuba experiences... fabulous clarity (regularly 100-200 feet) and the easiest drifting dive wall diving on the planet... lots of good operators there... Only real suggestion is to GO! Bob Fenner, just back from the Cook Islands and out to Mexico himself next week>

Baby maxima clams Hi Bob, I've been reading in the web searching for answers, and many times I end up reading you. I'm so happy I found this web site.... <And we're very happy it is being found... and useful> I had a baby maxima clam about 1". It died 4 days after arrived. It was doing well and I could find no parasites. The only thing I can think of is it had a very frayed foot and 2 days after arrival it lost it. I thought it was going to regrew it. Anyway, I constantly kept turning it up in the morning and afternoon, It was getting on its side every time, but I assure you it did not spent 1 hr. that way during the light hours at least. I have a 120 gal tank, with 120 lbs of LR, 60# of sugar sized aragonite, 5 small peaceful fish: 1 " in average gobies and one 2" Cirrhilabrus. I use Wet/Dry and big skimmer in a sump, and my main pump is 1200 GPH. Ammonia/Nitrites/Nitrates: 0, PH:8.2, Alk:5meql, temp: 81, and 300 ppm of calcium (I drip Kalkwasser at night 1 drop every 5-8 seconds). My lighting is 2 175W MH 5500K, and 2 Actinic FL ( I'm not if sure they are VHO). My tank is a 120 but is only 4 foot long: 2'W,2'H, 4'Long. So it is wide, not too deep, and the lights are more concentrated over the area. I want to keep Clams in the sand bottom. My questions are: What do you think happened to my clam, and Will I be able to keep clams in the sand bottom? Thanks a lot, Norberto. >> <Hmm hard to say with any degree of certainty what went wrong with this one specimen... but I suspect it was something(s) that occurred in advance of your receiving this animal that led to its demise... That is, cumulative insults from handling, poor water quality... led to its subsequent death. Reading through what you've listed as gear, water quality, I see nothing overtly wrong (Your lighting, calcium and alkalinity could be "higher", but they alone would not account for the loss), and would be inclined to try another specimen. Bob Fenner>

Re: Baby maxima clams I thought the Alkalinity was on the high side: 5 meq/L?... and the PH on the low side 8.2... I've been battling out to push the PH up... with no success... I've tried buffers, and Baking powder. The Buffer (Kent Marine) just dropped my Calcium, and the backing soda helped too little. I got the PH in 8.2 and don't want to risk months of dosing Kalkwasser on another addition... Maybe my kits are bad. They are SeaChem... look pretty good to me, but they are the only thing I've tried so far... >> <Not necessarily on the first two measures... 3 meq/l is what many folks consider reasonable for captive systems... but... I would cut back on the baking soda (not powder I hope/trust, unless you're cooking:))... doubt if you're kits are bad, but not too much trouble to test the testers... look into the Salifert, Hach products. Bob Fenner>

Re: Baby maxima clams Yes about 1 drop every 6 seconds from around 10 PM until 8 AM. (10 Hours) I have a 2 Gal doser that empties every 2 weeks... My Calcium is around 300 ppm. Do you think I should keep dosing that way, cut back (and how much should I cut back?), or dose more?... >> <Hmm, have you considered another form of calcium... like Calcium chloride? Maybe take a read through Bob Goemans last few months of TFH articles where he gives about the best recent rendition of how else to boost biomineral content and preserve alkalinity. Bob Fenner>

RE: Baby maxima clams What's TFH?... Where can I find those articles?... >> Tropical Fish Hobbyist magazine... Out of Neptune City, NJ. Maybe a store carries them or a library... where are you on the planet? Bob Fenner

RE: Baby maxima clams I'm in Atlanta GA, how about you? don't tell me you are in some nice beach please... >> <Hey, Atlanta's a nice town (though growing too fast, big for me...) am in San Diego (but out to the Cook Islands next week, don't scream), but a large library near you (like a college) will likely have TFH in their stacks...call, look around... and maybe subscribe. Bob Fenner>

Clams Hi, I am in the market to purchase a giant clam, either a maxima, or similar type. My alkalinity is about 10 DKH and Calcium is about 400 ppm. Lighting consists of 2 ,55 watt power compact fluorescents . One actinic and one 6700 day light. The tank is 16 inches deep ,it's a 20 gal High. Could I keep the type of clam I have mentioned above or other giant clam? If I kept one of the maximas or Croceas would I have to place them very close to the light , near the surface? If I kept a Derasa how far away could the clam be placed away from the light source? Thank You, Adam Matt >> Thanks for asking.... and for the depth of system, type of lighting I would place any of these Tridacnids on/near the bottom... the likelihood of environmental variability and toppling in shallower reaches/placed up on rock, is not worth the risk... Place whichever one you like near the middle on the bottom, IMO (of course). Bob Fenner

I need your advice - thank you Dear Mr. Fenner, I thank you for all of your advice given so far, from sharks to clams you have covered it all! But once again, I have come to you for help. Here is my final huge list although it needs revision. I hope you can help me figure out what is needed and what is not. My plan is listed below, yet my general drift for this plan is a display aquarium for my choice anemone/clown pair. Magnificent Sea Anemone (Heteractis magnifica)/Percula Clown Pair - mated (Amphiprion Percula). Here is my plan, please let me know what you think, the other inverts such as corals and clam all depend on anemone size and what it wants. I am concerned w/ having a Mandarinfish w/anemone. <And you should be... if the anemone is mounted high enough in the system, the Mandarin is probably going to be okay> And as you know the six line is only if I have a clam, for parasite control. I will have around 25 - 30 lbs live rock to create a base and wall along the back. My concern from there is the lighting. I know clams will thrive under so much lighting, but I may not have a clam therefore, should I go w/ another light option? Maybe 1 250 MH and actinic VHO's? <This is a sound idea. And to place the Tridacnid clam approximately under the brightest area under the MH> I am lost w/so much for a lil old display system. The cost for equipment is high, but I am able to get livestock at wholesale cost through a friend. Please help, you know more than most, and my friend wants me to stock up my tank to be w/the corals he listed. I thank you for all of your advice, and all you have done for the hobby! Thank you, Chris Anderson Reef Tank Plan Equipment List 58 gallon Oceanic Reef Ready Tank w/ Black Trim Black Oceanic Reef Ready Cabinet Black Oceanic Reef Ready Cap Environmental Tower Scrubber Skimmer (E.T.S.S) Reef Devil III w/ Iwaki Pump Hamilton Technology 36" Deluxe Aluminum System w/ two 175 watt MH and two 95 watt VHO actinics LifeReef Custom ETS Sump www.lifereef.com Red Sea Wave master Pro Kent Marine 35 GPD Maxima Hi-S RO/DI <Nice gear. I would utilize some activated carbon once a month in the filter flow path to lessen the likelihood of biochemical anomalies> Species List Blue Ultra Maxima Clam (Tridacna maxima) Magnificent Sea Anemone (Heteractis Magnifica) Xenia () Bubble Coral () Green Open Brain Colt Coral Finger Leather (Sinularia) Mushrooms Button Polyps Green Star Polyps Yellow Polyps Yellow Tonga Leather <Sometimes touchy, but gorgeous> Elegance Corals <Always touchy... ask to have someone help you pick out a very healthy specimen... place it low in the system (as in the substrate)... and read over the bits on Catalaphyllia/Elegance I have posted: Home Page > Hippo Tang (Paracanthurus hepatus)<Wait on this species for last, three months plus in> Clownfish - M/F (Amphiprion Percula) Cleaner Shrimp - M/F (Lysmata amboinensis) Banggai Cardinalfish - M/F (Pterapogon kauderni) Six Line Wrasse (Pseudocheilinus hexataenia) Assorted Hermits 12 Scarlets 2 Brittle Stars Mandarinfish (Synchiropus splendidus) >><And this fish for at least two months after the system is up and running> Keep dreaming, planning, and chatting,

I got a clam today, oh boy I received my first clam last Friday (3" Samoan Blue Rim Derasa Clam). I have 4 96 watt PC's 2blue 2dl over a 150gal. reef w/250lbs. lv. & a Berlin Classic everything else is fine. You had stated Pyramidellid snails can kill clams. Are these those 1/2 shelled night critters? What do they look like? Are there any other articles on keeping clams out there? I want to keep some clams but refuse to have another perish in six days before finding out just cause for this failed attempt. >> Pyramidellid snails are generally tan to whitish (to match the internal mantle color of their hosts) of much smaller size (1/4 inch are large), and come out, though hard to see, during light and dark hours (typically only found in/on the giant clam itself, not outside). They're shaped something like little pyramids, with a high mid-shell area, but you have to look really close to make this out. In a system such as yours I'd like to suggest placing the new clam(s) low/deeper in the tank the first few days, but ultimately (within a week), moving it/them up to shallower, brighter lit environs to sustain their symbiotic algae. These species need intense lighting. Much has been written about the giant clams of the family Tridacnidae, and their captive husbandry. Try using your computer's search engines for both terms, and also looking through the "marine aquarium clubs" (as a search term) as well. Many people have links to the information on care of these animals. Bob Fenner

Clams, supplements Hi, I'm interested in getting a Samoan Blue Rim Derasa Clam from f.fish express. What type of supplements should I add to the water? How often? >> I would "just" do regular water changes with a good salt mix (Aquarium Systems product, Tropic Marin), feed your other livestock (maybe the occasional/weekly single celled algae infusion to the tank in general), and pay attention to alkalinity (keep it above 3.5 meq/l) and calcium (above 400ppm)... and not worry about much else... Many ways to do this... the best with a calcium reactor... and test kits. Don't get involved with antagonistic mixtures of Kalkwasser, calcium chloride... or even "two-part" supplements without knowing what you're doing, and without testing. Sorry to state, there is no, no-brainer "just pour in one capful per this volume" of standard ACME do-all supplements. Bob Fenner

Clams... I am wanting to add a clam to my aquarium. I have a 75 Gallon with 4 48" VHO's (2 blue and 2 50/50). I have a large protein skimmer, wet/dry trickle system and also 65 - 70 lbs of live rock. The current inhabitants are: 2 pearly Jawfish, 3 yellow Coris wrasses, 1 six line wrasse, 1 coral beauty angel, 1 Lemonpeel angel, 1 Scopas tang 1 orange spot goby, 2 cleaner shrimp, 1 pistol shrimp, 1 brittle star, 1 serpent star, 2 cucumbers and lots of hermits and snails. I am adding 1 harlequin shrimp, replacing the Scopas with a purple tang. I also have lots of mushroom corals, some green star coral and a gold crown Sarcophyton and a small rose bubble anemone. Everything seems to be doing fine. What would I need to do to add a clam? <Needs to be placed high in your tank... maybe no more than four inches below the surface... need bright lighting> Would I need to start adding calcium? <Yes, in some format... these animals need high calcium and alkalinity> what would be the best way for the least money. Not the cheapest, but best on both <?> fronts. <Calcium can be supplemented with Kalkwasser with care in preparation, administration (at night, trickled in with brisk circulation... maybe hooked up to a venturi intake and an all plastic air/needle valve onto a powerhead... To prevent negative interactions with alkaline materials> I don't want to pay $400 for a calcium reactor. also, I am thinking of getting rid of my serpent and brittle stars because I heard they may take fish at night. what can you tell me about that? <The principal "green" species is notorious for eating fishes at night when it is large, hungry> thanks. Chris Madsen >> <You're welcome. Bob Fenner>

Clams Bob- Are two 96w PC strong enough lighting for a clam? The tank is 18" deep so I am guessing I would have to put it somewhere in the middle of the rock. Thank you, Rob >> A Tridacnid? Should be enough at even the bottom for sustaining any of the given species available... DO try to secure a cultured individual (as opposed to wild-extracted)... Bob Fenner

Clam attachment Dear sir: I am having trouble getting my new squamosa clams to attach to some pieces of rock. They were getting knocked over but now they are in their own tank. What can I do to get them to attach and more importantly to prosper? What are their food and water quality requirements. I must admit I don't know much about clams and I am trying to have better than trial and error success. I am very successful through the years with fish and soft corals. I even breed maroon clowns. Not that it matters. Thanks, Bevan Cotton >> To further Tridacnid growth, attachment, health in general... Keep biomineral and alkalinity levels up... periodically feed algae cultures or introduce algae foods (from paste, frozen, dry sources), hook up a refugium, mud/muck filter, add some (more) peaceful fishes whose wastes, movement will add to the clam's well-being... Bob Fenner

Maxima clam "freshwater dip" I recently purchased a maxima clam. It had two things attached to it. One had a shell like the clam it was attached to, it attached to the clam with fibers that ripped when I pulled it off. The other was sponge like. I didn't know if these were parasites but I didn't want to take any chances. My question is, I know that parasites can kill clams, can I do your recommended freshwater dip for my clam to rid it of any parasites that I might not find? Thanks, Jared >> Hmm, probably a good idea to do as you did with the likely innocuous "hitchhikers"... and no to the freshwater dips for Tridacnids... as a means of controlling parasites... but yes to the use of animals like Pseudocheilinus wrasses for eradicating many Clam enemies... like Pyramidellid snails. Bob Fenner

Clam sick I have a derasa clam that is about 8 months old and had grown about 3/4 inch with good mantle extension. Two days ago I performed a routine 15% water change and removed some old accumulated brown algae from the back of the 75 g tank (physically removed most, but much was simply scrubbed off into the tank). I use the Aquarium Pharmaceutical, Inc. resin filter. Since that maintenance, my clam has looked 'sick' -poor mantle extension on 1/2 his body and he/she is not fully opened. No bleaching is present. Although I have occasionally had problems with brown algae, my overall water parameters have been good (including Ca). Other livestock looks fine, but I did lose a flame angel to ich 1 month ago. Something happened with that maintenance period but I am not sure; could removing the accumulated brown algae release toxins into the water. Is there anything I can do, or is demise certain? >> Yes to the release of toxins from the Brown algae removal... not likely to the clams certain demise. Do consider increasing your lighting to change the brown types of algae over to more light-favoring greens... either by adding more watts, increasing light period or both. Bob Fenner

Lights I have a 30L reef tank and currently run two 36in VHO lights, 1 blue and 1 white. Is this enough light for hard/soft corals and clams? Also how long should I run the lights, and between what times is best? Thanks, Rob. >> For many hard corals... most every soft coral offered in the trade... and moderately for giant clams... With these sorts of animals twelve hours for the white, fourteen for the blue... an hour before/after the white. Bob Fenner, who says/keys, "you're welcome".

Clams I have a few questions first off I was wondering if there are any butterfly fish that a reef safe? Second I wanted to know what kind of lighting is needed to keep clams alive? >> IMO yes... some of this family (Chaetodontidae) are largely zooplanktivorous (though, of course there are gradations to almost absolute coral polyp feeders). Some examples: The Longnose Butterflyfishes of the genus Forcipiger... Chelmons, Chelmonops species, the Bannerfish genus members: Heniochus, the Raccoon Butterflyfishes, Chaetodon lunula and C. fasciatus... There are others, and the family, it's uses detailed in articles stored at www.wetwebmedia.com Clams? As in giant clams (family Tridacnidae) require bright/intense, full-spectrum lighting to optimize their growth and color... most folks use Very High Output Fluorescents on the low end to Compact Fluorescents and Metal Halides on the high... depending on tank depth, desired effects. Bob Fenner

Clams? HI, I am interested in buying a Deresa Clam for my reef tank, but I don't know much about them. Could you give me some information. how and what it eats, what will eat him? How to care for it? What kind of conditions it needs? How do I know a good specimen from a bad one? >> This is a big and important set of questions... Are you sure you're ready to invest in and care for a Derasa giant Clam? They're a combination of filter feeder (mostly single celled algae) and photosynthates (using nitrates, phosphate and more with light to make carbohydrates... via endosymbiotic algae in their mantles)... How to care for one? You mean good water quality... and intense, full-spectrum light... ample calcium and other alkaline earth materials...Many fishes and invertebrates will sample Tridacnid clams... and they have some notable parasites/predators... like Pyramidellid snails... Good specimens? Open, not chewed... captive bred and reared... i.e., not wild-collected. Bob Fenner, who says this is a six minute version/glimpse of what you really need to know re these animals... keep studying

Tridacna clams I have a 125g reef that has been going for one year. The six fish all seem healthy along with an extremely large and happy bubble coral I've had for four years. I have numerous other corals that are in good shape also. I have two 175w halide lights. In the last four weeks all three of my Tridacna sp. have died. They looked good for a few months then started to gape. My nitrates are high (greater than 10ppm nitrate nitrogen). Is this the problem? Thanks, George >> Wow, and sorry to hear of your clam losses... I doubt if the nitrates had much to do with their demise. Some folks who culture them have much, much more nitrate in their water... some on purpose/by design. So what does account for their deaths? Not much clues in this email... the Plerogyra (Bubble Coral) is doing fine... enough light... Are you "supplementing" your system chemically? This is the usual, or most common cause of Tridacnid loss... Any chance a predator is involved? Did you note any "chew" marks on the clams mantles or other soft body parts? Do you know what Pyramidellid snails look like? How long were the clams "gaping" before perishing? Did they go all at once? Which died first, largest, smallest, species... Bob Fenner

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