Clam Wipeout - Iron Dosing, Disease?

[mwp]

OK, guys, I am truly stumped. I asked Barry @ clamsdirect, he is arguably stumped too. For those of you who know how I run my tanks and have nothing to contribute other than "flames", save it. If this was a stocking/maintenance type issue, other more sensitive organisms should have kicked the bucket long before the clams, and well, the cardinals wouldn't be breeding and the SPS would be ultra PO'd right now. The ONLY THING that's having issues are the CLAMS and it's BAD NEWS!

 

I'm not going to rehash the details here, I hope that you can all accept that I test "EVERYTHING" under the sun when it comes to water quality. Things have been going FINE in this tank. The water is "pristine" and everything has been prospering in this tank, including our Tridacnas.

 

Back on the 19th & 20th, we lost 2 of our tridacna clams and a flame scallop. This was alarming, they went down "hard and fast"; I did a water test (spotless) and 15% water change. Things looked OK otherwise, except for one Crocea who seemed a bit "unhappy", not fully extending his mantle, perhaps only 75% of his maximum. We had to leave for Xmas vacation for 4 days. Sometime over this trip, the "unhappy" crocea declined fast and died..can't say when; it was found by our "aquarium sitter" a few hours before we returned home.

 

Since our return, we have lost another crocea, a maxima, a squamosa...the derasa looks like it will be dead by nightfall. In the last 7 days we have lost over 50% of the tridacnids in the tank. EVERYTHING ELSE IS HAPPY (heck, the cardinalfish are breeding).

 

After reviewing all my notes (I keep a log of EVERYTHING I do), the only thing that I'm kinda leaning towards is the dosing of Iron that I started on December 14th. We're using Kent's Marine Iron at a rate of 1 drop per 5 gallons daily. Prior to and After starting this Iron dosing routine, we have never had ANY detectable levels of Iron / Chelated Iron (via Seachem's Iron Test). Our Macro Algae has seen a "boost" and our second tank which is also now getting iron has had NO problems (however, there are no Tridacnids in that tank).

 

We've ruled out EVERYTHING (and I mean EVERYTHING) except for the IRON DOSING or DISEASE. I'm hoping maybe someone can rule out the Iron dosing (because they're doing it with the same products at the same rate and have the same undetectable levels WITH TRIDACNAS in their tank). Ruling out Iron would only leave me with Disease...a horrible conclusion that somehow I can "swallow" knowing that I have done EVERYTHING I POSSIBLY CAN DO...at least we can perhaps then try to "treat" this mystery.

 

I welcome any and all crazy thoughts here, but save the flames/I told you so's cause the "I told you so's", well, I think up until this point our tank has completely disregarded your opinions and flourished.

 

MP

[tinyreef]

have you qt'd and 'tested' the iron separately? bad batches of whatever have been known to exist. could be you've got a 'bad' batch. wouldn't completely explain why the clams/mollusks seem to be the only things affected though (at least to my satifsfaction).

 

disease is a definite possibility but it usually kills with a new addition/event (e.g. livestock, rock, LFS waterchange, new batch of chemicals/food, etc.) rather than a spontaneous occurence. although, stress events can trigger latent diseases ime. something the livestock had been successfully fending off can gain an advantage when the host livestock undergoes additional stress (e.g. your vacation).

 

although the speed to which you're saying the decline occurs falls within disease timing. actually, it falls on the long side of that timing imo.

 

could be a specific toxin that affects mollusks and not the other livestock. i had a similar situation recently affecting hermits and snails but nothing else (i.e. corals, fish, algae, worms, etc.).

 

i resolved it (i believe it's resolved) through multiple chemical media ad/absorbers and waterchanges. nothing dramatic like a 50% change but just an increase in frequency for me, i.e. 10%-weekly and carbon/weekly, and Poly-Filters 3~4 days.

[NEVER SATISFIED REFFER]

im for stop the iron!!!!

[RayWhisperer]

Yeah, just seems too likely a suspect, can't be coincidence. I don't proclaim any expertiese in clams, but this is where I would start if it were me.

[SLOreefer]

sorry if i missed it but were there any new additions within the few days befoer the deaths started? when i worked at an lfs there was a clam epidemic if you will. it seemed to be nationwide, clams from a certain area came in a shipment and spread disease and killed off many clam tanks including my buddies 14 clams in his 180, didnt affect anything like sps

 

im sure if you searched rc you could dig up some stuff about it, this was about 3 years ago though, it could happen

 

my first vote would be the iron though since it is the only noticeable change

[mwp]

THANKS GUYS. Seems like a LOT of the responses (including my own deductions) lead me to the IRON. Yet somehow I still feel that at the low dosing (and consistently undetectable levels) that it "can't" be the cause.

 

I did get a rather interesting and "short" response over on reefs.org to this same original post...a user who introduced a clam and 3 weeks later they all started croaking. HMM. That pretty well matches up with MY timeline...our last clam addition was on Dec 6th.

 

I have to say, from my observations this is certainly going through the bivalve population as if it were a disease. Only bivalves affected, length of time in the tank seems irrelevant, at first a few go down, then more etc...

 

By all means keep the ideas coming....most all of the "irreplaceable" clams have died...I'm really hoping to keep our Blue-Spotted Crocea around as he's a one-of-a-kind in my book. Arguably the most disheartening loss was the oldest crocea...I remembered looking at him and feeling great satisfaction with how much he had grown and how "perfect" "he" looked...talk about having such great attatchment to such a bland purple clam

 

The only other note I can contribute at this time is that 3/6 remaining bivalves look happy, the 2 Hippopus and our last Squamosa. The Derasa and Gigas aren't fairing so well, and the crocea produced a huge mucus coat this afternoon....yup..sounds more like DISEASE than a toxin (like Iron).

 

MP

[Wiggawam]

Pyramid snails! With the new clam points right too it but I figure Barry would have told you that. I don't know have any idea if you have a sandbed or anything but I would check at night ASAP!

[bobioden]

What was the reason for starting the Iron dosing? Just curious.

 

Bob

[Gwoardnog]

Yea, definately look for those snails.

Stopping your iron dosing isn't going to hurt anything either. Might as well give it a shot.

[Six]

pack that many animals in a tight space and your bound to get disease. when disease does come, it will wipe out the entire stock because the animals are of the same species.

 

same with montipora species. if you get a disease on one colony it doesnt take much to wipe out the entire tank of that genus. acros can do the same.

 

or maybe you dosed too much iron tho im not sure why youd be dosing anything but phyto/nitrate and calcium.

 

sorry about your luck, but it doesnt sound suprising IMO.

[tinyreef]

i think he does have pyramids. on rdo he notes they're a persistent yet manageable infestation (at least he says he has them under control). they limited themselves (the snails) to the sandbed it seemed.

 

maybe the metal poisoning weakened the clams to the point of succumbing to disease. or it could be metal poisoning anyways.

 

i remember the clam epidemic from a couple of years ago. i lost one clam (crocea) to it and it weakened a squammy almost to the point of death. after recovering, the squammy then died from ammonia poisoning from the office cleaning crew.

[icenine]

I agree with Tiny and Six. I've seen postings about this tank before and there are a whole lot of animals here even in addition to the five clams, btw what is the lighting here again MWP? The tank looked nice over the summer I know, but it was pretty jammed. Anyway regardless, where the load is that heavy little things can send a system spiraling down quickly. While disease or parasites may have been manageable throw one more problem into the mix and things become unsalvageable. I too would be interested in finding out why you were dosing iron. I still don't dose anything in my tanks, my water changes do a really good job of trace element replacement. ....I'm sure if I have that many clams I'd be doing something more about calcium, but what's up with the iron?

...and does a flame scallop ever live in anyone's tank? They should rename those things take-your-tank-down-in-flames scallops.

Good luck!

(p.s. post pics please)

[mwp]

All good points. I'm really leaning towards disease at this point...get it to a certain point and sure, it will take everything down. Happens with fish all the time, so why not clams? The only difference is that most "fish" afflictions we can treat and prevent...can't say the same for clams. Six, you raise a good point with regards to "packing them in".

 

Yup, we have pyramids at very low levels (I.e. the deresa kicked the bucket today, had a whopping 2 little pyramids on it.) Other than being a possible vector for spreading a disease, they are not a direct problem (nor do I believe that pyramids would be responsible, having been present from the get go...why would they suddenly wipe out ALL the clams in a week's span?)

 

Yeah, by many opinions this tank is "overstocked" and "underlit". HOGWASH...we have cardinals spawning left and right, the clams were growing, sps growing, macroalgae to the gills. This IS the "Algae/Cardinal/Clam" tank afterall. Nitrates remained well under control, everything was FLOURISHING. This wasn't a case of only the new clams going down, or the new clams going down first, or for that matter even immediately tied to the addition of clams at all. Instead, they had been present for a couple weeks and were settling in VERY NICELY. Our last remaining "HAPPY" Tridacna is one of the "new" ones...the Crocea. If he makes it and everything else dies, I think I'll know exactly which clam is a likely culprit for bringing in a disease, if that's the case.

 

For all of those who wondered why I started dosing Iron, let me provide more information. I regularly dose Seachem's Reef Calcium and Reef Complete (generally alternating) to maintain calcium levels...the clam tank sure sucks CA levels down quickly. I use Reef Buffer or Reef Builder depending on where Total Alkalinity and pH test out. Reef Plus (general vitamins+) is dosed as well. Reef Iodide is rarely used in our clam tank, and only after testing existing levels (the "traditional" reef tank uses LOTS of Iodide and gets dosed almost weekly).

 

We were having good macro-algae growth but I wanted to kick it off even better. Thus I tried dosing Iron. I sure have to say that the IRON dosing DID HELP, and the fact that through all the dosing no detectable levels of Iron / Chelated Iron ever showed up, it is most likely getting used. The growth rate of our Macro Algae has probably tripled/quadrupled since starting the iron dosing; we're having less die-off of individual fronds and as a whole, the growth is thicker and more lush. There is almost no micro aglae present in the tank and coraline algae growth seems to have increased dramatically as well. Were it NOT for the "wipeout" of our clams, I'd say that the IRON was a SMART move and really helped...only due to our clam deaths am I questioning the Iron dosing. Had I been dosing "too much" I would have expected at least "detectable" levels to show up on Seachem's test (low range)...but even then I've had NOTHING in the way of detectable Iron. 1 drop per 5 gallons daily..it's "nothing", but it was enough to improve our macro-algae growth.

 

The flame scallop; he's the strange one. I wondered if he perhaps brought in a disease organism that ordinarily a tridacnid wouldn't encounter (and thus wouldn't have any resistence to). At first that seemed like a good notion, except for the fact that the Flame Scallop should have been OK in that type of scenario. Rather, the flame scallop went down "fast and hard" like any clam that has started showing symptoms.

 

I hate to say it, but all signs point to disease. Our remaining squamosa was looking A+ last night...today he's on a rapid decline and I suspect will be dead by tonight or tomorrow morning.

 

The only other notes; we're NOT running a protien skimmer (relying on Purigen). I may have mentioned this already, but the carbon was relatively "new". I've been contemplating the addition of a UV to this tank...if we are facing disease, and it was spread by water, not a biological vector like pyramids, then a properly set-up UV would have prevented this calamity.

 

MP

[RayWhisperer]

Our last remaining "HAPPY" Tridacna is one of the "new" ones...the Crocea. If he makes it and everything else dies, I think I'll know exactly which clam is a likely culprit for bringing in a disease, if that's the case.

Very good possibility, the "carrier" is often resistant, however, anything that takes all out so fast, just doesn't seem likely that anything could have a resistance to.

I've been contemplating the addition of a UV to this tank...if we are facing disease, and it was spread by water, not a biological vector like pyramids, then a properly set-up UV would have prevented this calamity.

I can't say I would agree. Sure, it would have slowed it down somewhat, maybe even stopped it after only one or a few deaths.

[bobioden]

Do you by chance have any pics? I say that as I lost a Maxima after a year and a half, and I could never figure out why. Did the mantles recede on yours?

I too had pyramid snails in my tank, but also a 6-Line Wrasse who kept them in check.

 

Bob

[mwp]

I DO have some pics. Especially "potentially interesting" is the 24 hour "turn around" in our last squamosa from "healthy" to "not healthy"...an overnight change. Those pics are still stuck in the camera though...I'll post them later on.

 

The other pics I have are a couple days old. First, our unhappy gigas / derasa (the gigas just looks even worse now if you can believe it, whereas the deresa is now dead).

 

 

This second pic is of what is now our only happy clams; the "new crocea" and potentially suspected "carrier" although it's too early to tell in my book..he could still go down. We're left with the crocea, the gigas, and two Hippopus (one in the pic). The only clams that seem unaffected at this point are the Hippopus and the last crocea. Everything else has died at this point, 'cept the gigas which will probably kick the bucket today.

 

 

Now, a lot of folks reference crocea as the "most difficult" of the clams, with maximas up there as well. Surprisingly, our longest lived clam was a crocea, growing like a weed before this wipeout. And, our last remaining "healthy" clam is ALSO a crocea. Makes me wonder if perhaps conditions in our tank are "perfect" for croceas and less ideal for other clams???

 

FWIW,

 

MP

[steelhealr]

Did the flame scallop seem to go first? SH

[Gwoardnog]

Getting the clam eating snails out of your tank might make you clams a little more healthier and more able to fight off said disease....

 

just a thought....

[mwp]

The Flame Scallop was lost on day #2 of this ongoing plague.

 

Matt

[mwp]

The sad sad news....our gigas croaked (as expected) this evening. At this time the remaining clams (blue spotted crocea and 2 hippopus) look healthy. So we're basically down to 1 Tridacna. I dont' even want to count how many died...it's on the order of "several"...at least a half-grand in clams

 

Meanwhile everything else is doing A+. Go figure.

 

MP

[icenine]

Well.. you really did have a lot of clam in a system that well, is not really suited for clams at all much less the number you invested in.

I'm not claiming to be an expert, we are all at differnet levels of learing, but we are all still learinging in this hobby. At least to me to stock the tank the way you did was risky.

[tinyreef]

Other than being a possible vector for spreading a disease, they are not a direct problem (nor do I believe that pyramids would be responsible, having been present from the get go...why would they suddenly wipe out ALL the clams in a week's span?)

perhaps they could have just been a contributory factor. i.e. their presence/parasitism weakened the clams to the point to be unable to fight off the illness (?-still unknown if it even is such).

 

For all of those who wondered why I started dosing Iron, let me provide more information. I regularly dose Seachem's Reef Calcium and Reef Complete (generally alternating) to maintain calcium levels...the clam tank sure sucks CA levels down quickly. I use Reef Buffer or Reef Builder depending on where Total Alkalinity and pH test out. Reef Plus (general vitamins+) is dosed as well. Reef Iodide is rarely used in our clam tank, and only after testing existing levels (the "traditional" reef tank uses LOTS of Iodide and gets dosed almost weekly).

 

We were having good macro-algae growth but I wanted to kick it off even better. Thus I tried dosing Iron. I sure have to say that the IRON dosing DID HELP, and the fact that through all the dosing no detectable levels of Iron / Chelated Iron ever showed up, it is most likely getting used. The growth rate of our Macro Algae has probably tripled/quadrupled since starting the iron dosing; we're having less die-off of individual fronds and as a whole, the growth is thicker and more lush. There is almost no micro aglae present in the tank and coraline algae growth seems to have increased dramatically as well. Were it NOT for the "wipeout" of our clams, I'd say that the IRON was a SMART move and really helped...only due to our clam deaths am I questioning the Iron dosing. Had I been dosing "too much" I would have expected at least "detectable" levels to show up on Seachem's test (low range)...but even then I've had NOTHING in the way of detectable Iron. 1 drop per 5 gallons daily..it's "nothing", but it was enough to improve our macro-algae growth.

not totally agreeing on this viewpoint. the coralline growth could've been from the slowing down/weakness of the clams allowing for more resources to be available for the coralline (versus the clams). you didn't alter your normal ca/alk supps so they (ca/alk & nutrients) had to still go somewhere when the clams basically shutdown "growth mode" and switch over to "defense mode."

 

the same thing goes for the macro imo. clams are considerable nutrient users/processors. if we were talking about sps i would also support the thought process you state above. but the clams makes that more difficult/complicated imo. it could be like you describe but it could also not be.

 

i'm not sure if slow metal poisoning would show up in the tests. i.e. if it's being absorbed into the clams' biomass, it wouldn't be left around to be registered on the tests. (not a chemist myself) but does chelated iron show up well on 'typical' iron tests? i thought chelated forms mask themselves or are more difficult to detect. (i have no frickin' clue, just thought i heard that somewhere)

 

to continue the "test", you might want to continue to dose iron. i now that sounds weird but the point would be to see if the macro is uptaking the whole amount versus a significant portion was being absorbed by the clams. i guess you could also do a necropsy on the clams and test the tissue matter ($$$).

 

i'd also suggest a "fixed" test. mix up a small batch of sw (about 1g) and dose it with iron while it's still in a bucket/container. test that or repeat dosing until you reach a readable level. that should give you some "calibration" of the test kits.

 

The flame scallop; he's the strange one. I wondered if he perhaps brought in a disease organism that ordinarily a tridacnid wouldn't encounter (and thus wouldn't have any resistence to). At first that seemed like a good notion, except for the fact that the Flame Scallop should have been OK in that type of scenario. Rather, the flame scallop went down "fast and hard" like any clam that has started showing symptoms.

maybe the flame didn't have as much reserve or options to fight like the clams though. i've always thought of flames as "leaner" organisms than tridacna (photosynthetic) livestock. both feed but the clams have light and (imo) bigger reserves/fat to draw upon.

 

the flame could've just been overwhelmed more easily with no second nutrient source, i.e. photosynthesis. just some thoughts

 

i think (it looks like from the pics) the dreaded disease factor. some clams do survive it though. good luck!

[mwp]

Icenine, In some respects you're right...lots of stock = lots of cash exposure = "risky"

 

Despite our wipeout, I wouldn't call the clam tank a risky proposition in general though as up until this point everything was going well, and in fact, everything (besides the Tridacnas) are STILL doing well. Heck, 14 fish, tons of macro, pristine water, 6 unsuccessful spawnings of the Cardinalfish between 2 species all in a "24"....and our first "overstocked" and "underlit" nanocube is going gangbusters as well...

 

I don't look at this incident as a sign that I've "crossed the line" or done something that just "can't" be done though. All my experience, the "chemistry" of it all, it *should* work and up until this point, it DID work. So this was just a setback...the worst part was, after our most recent (and supposedly last/final addition) we were pretty much ready to just sit back and enjoy...we had gotten the tank to where we wanted it and were just happy to watch it grow.

 

Now, I simply feel we have to start over down the line. Sure, there are improvements that can be made in the setup (I'm still eagerly awaiting NanoCustom's 2005 lighting mod, if/when it arrives, so I can bump up the lighting). However, it almost seems that we didn't need any additional lighting as most of the clams were actively putting down new growth prior to this catastrophe.

 

It happens...living things don't live "forever"....

 

Matt

[mwp]

perhaps they could have just been a contributory factor. i.e. their presence/parasitism weakened the clams to the point to be unable to fight off the illness (?-still unknown if it even is such).

 

Indeed, I've thought about this as well. However, my conclusion based on my observations is that the pyramids are relatively speaking a non-issue other than being a possible vector. Only trouble with even the vector theory is that the pyramids have remained fixed to the substrate dwelling clams...NEVER found them on the clams I perched above on the rock ledge. I've also never found them on the Hippopus clams. With the last 2 clams on the sand (besides the one Hippopus) going down, I found 2 pyramids on the derasa's shell, and 1 on the Gigas. Seldom have I ever found more, and as always, they're manually destroyed on sight (yup, pulled the clams up, used tweezers and got ALL those little guys).

 

not totally agreeing on this viewpoint. the coralline growth could've been from the slowing down/weakness of the clams allowing for more resources to be available for the coralline (versus the clams). you didn't alter your normal ca/alk supps so they (ca/alk & nutrients) had to still go somewhere when the clams basically shutdown "growth mode" and switch over to "defense mode."

 

That's definitely a fair point, but again my observations lead me to a different conclusion. I dose elements including calcium and iodide based on testing results, and over the last few weeks I had to up my dosing of CA to the point where I was dosing daily, or even twice a day, just to maintain the levels. I still feel that the Iron was indeed responsible for the increased algal growth - now that I've stopped dosing Iron, guess what's stopped growing as fast............

 

the same thing goes for the macro imo. clams are considerable nutrient users/processors. if we were talking about sps i would also support the thought process you state above. but the clams makes that more difficult/complicated imo. it could be like you describe but it could also not be.

 

I agree on the general concensus that clams use a LOT of nutrients...that's partially why I kept so many. Everything else is the same in the tank with regards to the fish, the urchin, but when it comes time to harvest algae this week I really won't HAVE ANY considerable new growth to harvest. Another part of the equation that we'll have to wait and see what happens to my nitrate levels with a whopping 14 fish......I don't really know how much nitrogen these clams were "fixing".

 

i'm not sure if slow metal poisoning would show up in the tests. i.e. if it's being absorbed into the clams' biomass, it wouldn't be left around to be registered on the tests. (not a chemist myself) but does chelated iron show up well on 'typical' iron tests? i thought chelated forms mask themselves or are more difficult to detect. (i have no frickin' clue, just thought i heard that somewhere)

 

Your information is probably correct - a standard Seachem Iron test takes about 2 minutes, but you have to wait 30 to get results that include Chelated Iron. I let a test sit for 2 hours once...even then didn't get ANY results on the regular AND low range tests. And it's entirely fair to assume that the CLAMS could have been taking up the Iron along with it's "intended targets"....I hadn't really thought about that considering how much increase I saw in the Macro Algae growth.

 

to continue the "test", you might want to continue to dose iron. i now that sounds weird but the point would be to see if the macro is uptaking the whole amount versus a significant portion was being absorbed by the clams. i guess you could also do a necropsy on the clams and test the tissue matter ($$$).

 

Well, as I'm running two tanks I have NOT discontinued the Iron dosing in the non-clam tank - it too never tests out for Iron. As there's only coraline, a tiny tuft of Halimeda and another Red Macro Algae, I'm not sure what to say. The "red stuff" always grew slowly and tends to break off pieces that float around and settle elsewhere..it's never been one I've had to harvest. The only observation I can make in the other tank is that Coraline Algae growth does seem a bit more "vibrant"...

 

i'd also suggest a "fixed" test. mix up a small batch of sw (about 1g) and dose it with iron while it's still in a bucket/container. test that or repeat dosing until you reach a readable level. that should give you some "calibration" of the test kits.

 

Not a bad idea at all, I'll have to give that a shot!

 

maybe the flame didn't have as much reserve or options to fight like the clams though. i've always thought of flames as "leaner" organisms than tridacna (photosynthetic) livestock. both feed but the clams have light and (imo) bigger reserves/fat to draw upon.

 

We all know that Flames are touchy critters...I figured the tank was ready as I have dusters showing up left and right every day. It did well for a while, the the first clam went down, and that same day the scallop turned to a shrunken mess.

 

i think (it looks like from the pics) the dreaded disease factor. some clams do survive it though. good luck!

 

Thanks...at this point there's not much luck to be had...not much left to "save"! Judging by the way this has progressed from clam to clam, it really just "feels" more like disease to me. A poisoning by Iron dosing just is looking less and less likely the father we get out from the last dose in the timeline.

 

I'm watching our last remaining Tridacna, the "newest" crocea, and all day today it was outputting mucus off it's mantle again. For the last few hours this evening, before I turned out the lights, it looked to be at only 75% of it's typical mantel extension...not a good sign from what happened with all the others. Remember, this clam DID put down byssal strands and WAS attached within a few days of introduction...only to drop those strands and "detach" earlier thise week. At this rate, I don't expect it to be alive come Sunday if it's now coming down with our unknown plague. The Hippopus seem to be totally "oblivious" (thankfully).

 

FWIW,

 

Matt

[Nuhtty]

Clam Perkinsus Disease.

 

Perkinsus marinus (or similar protozoa) affect oysters, abalone and clams.

 

High iron levels cause these protozoa to run rampant, thereby destroying the animals.

 

Low iron levels, or nonexistant iron as you had before, cause the metabolism of the protozoa to remain slow thereby keeping the pathogen in a dormant type state = no harm to the clam.

 

Unfortunately there is nothing you can do at this point. I wouldnt add any more tridacna to the system.

 

Sorry to hear about your clams.