PMD spreading among Tridacna and FWD is not affective so far. Please HELP!

[Madison Reef]

I've got a baby maxima clam without any new shell growth on Feb 22nd from a well known vendor. While in QT, I did not find any pyramid snails, but it appeared that the baby maxima had PMD. I performed FWD before putting it into DT hoping that FWD would cure PMD. That said clam is still having the same issue (no shell growth and PMD) and another maxima that I got little more than a year ago is now having the same symptom. I assume that whatever is causing irritation of the new clam transmitted to the old clam. My previously healthy maxima is growing on the bottom of my tank so are my acros so I doubt that it's lack of light.

My question is that even though FWD did not cure PMD of newly acquired clam, should I continue considering FWD of both clams and move it to QT? Is there any other option to treat those clams? I do have fresh QT that I can control water parameter well enough and I can put any kind of lighting (t5, LED, or halide) to lessen the stress of acclimation.

Lastly, I understand that PMD can spread among Tridacna species but will it affect Hippopus?
According to clam master @OrionN "PMD pathogen does not affect bivalve other than the Tridacna genus." But, I just want to make sure that it will not affect Hippopus or any other non-Tridacna species.

Thank you in advance.

 

[OrionN]

I've got a baby maxima clam without any new shell growth on Feb 22nd from a well known vendor. While in QT, I did not find any pyramid snails, but it appeared that the baby maxima had PMD. I performed FWD before putting it into DT hoping that FWD would cure PMD. That said clam is still having the same issue (no shell growth and PMD) and another maxima that I got little more than a year ago is now having the same symptom. I assume that whatever is causing irritation of the new clam transmitted to the old clam. My previously healthy maxima is growing on the bottom of my tank so are my acros so I doubt that it's lack of light.

My question is that even though FWD did not cure PMD of newly acquired clam, should I continue considering FWD of both clams and move it to QT? Is there any other option to treat those clams? I do have fresh QT that I can control water parameter well enough and I can put any kind of lighting (t5, LED, or halide) to lessen the stress of acclimation.

Lastly, I understand that PMD can spread among Tridacna species but will it affect Hippopus?
According to clam master @OrionN "PMD pathogen does not affect bivalve other than the Tridacna genus." But, I just want to make sure that it will not affect Hippopus or any other non-Tridacna species.

Thank you in advance.

I NEVER said PMD does not affect clams other than Tridacnid. I just done have an experience on this.
There are many different causes for clam mantle to retracted. PMD is only one of these diseases. If you clam did not improved with FWD, then it most likely did not have PMD
Good luck

 

[Madison Reef]

I must be confused with English, sigh. Please help me understand.

So if it is not PMD, is it still possible whatever causing the irritation of the old clam got transmitted to the new one? If it is indeed not PMD, what would be a good treatment plan?

Thank you for your help!

 

[xjiang7]

The pathogens that affect Tridacna clams are poorly understood. Adding a new clam that causes demises of existing seemingly healthy clams have happened to me many times. FWD has never really helped me neither. I suggest after the clams dies off do a clam free period and start over with the QT process. Don't place a new clam into your DT until you see new growth on it

 

[Shirak]

Pictures of the clams?

 

[Madison Reef]

The pathogens that affect Tridacna clams are poorly understood. Adding a new clam that causes demises of existing seemingly healthy clams have happened to me many times. FWD has never really helped me neither. I suggest after the clams dies off do a clam free period and start over with the QT process. Don't place a new clam into your DT until you see new growth on it

How long do you suggest "clam free period" for DT? Should I at least try to separate them? Would it be helpful? I do have another (second) QT that is currently used for pods which can be easily turned into a invert/coral QT (the new clam in QT 1 and the old clam in QT 2 separately). Even if the pathogens are unknown, would it be a good idea to treat them like we treat fish with, say, bacterial infection? (of course I do not know what is causing the issue but at least it's better to give it a try rather than watch it suffering) I just can't handle watching the old clam that I cared and loved slowly perish.

Your help is much appreciated. Thank you!

Pictures of the clams?

I will upload the photo of both clams tonight, at the end of photoperiod. Thank you for your willingness to help!

 

[OrionN]

I must be confused with English, sigh. Please help me understand.

So if it is not PMD, is it still possible whatever causing the irritation of the old clam got transmitted to the new one? If it is indeed not PMD, what would be a good treatment plan?

Thank you for your help!

That was when we were talking about other invertebrates like filter clam anemones and snails and the likes. I was able to clear my tank by just treating Tridacna clams. I never keep a Hippopus. I can confidently say that the PMD pathogen does not affect snails and filtering, non-photosynthetic clams. I would not confidently say Hippopus is in that group.

 

[OrionN]

PMD is just one of the diseases that affect clams. The symptoms are very well documented in my write up. Anything that irritated the clam will cause mantel retraction, thus not all mantel retraction is PMD
This was my observations of this disease in my tank a quarter of a century ago.

I struggled with this disease for several years. These were my observation of Pinched Mantle Disease:

• The previously healthy clam, newly infected will appears healthy but will have retraction of one area of the mantle. This was not true with clam that was send to me sick, but always true with clams that were healthy then infected in my tank.
• The irritated, diseased mantle always retracted at the same place and mantle retraction spread from there.
• This disease affected all five species of Tridacna in my tank.
• The disease was slow in onset and healthy clams can live for months with this disease. My large Gigas live for over 1 year with the disease until I cure him with FWD
• Clam mantle retraction spreads slowly from one area to adjacent area, rarely skipped area of mantles.
• Disease spread from adjacent clams most easy but there are infections of clams at distance location. This is much more common when the numbers of clams that were infected in a tank increased.
• Clams look better in AM, but mantles become much more irritated, more contracted by the end of the photoperiod.
• As the days go on clams secrete strands of mucus that can be seen extended from the disease mantles
• As the disease progress, the mantle retraction worsens and the diseased clam dies of starvation.

 

[OrionN]

Correct diagnosis is everything. Wrong diagnosis and treatment can kill the clam and does not help. It is like treating the lung lesion as cancer when it is actually an infection.

Pictures from my tank in 2001. The Crocea in the first picture and the Blue Maxima in the second picture had PMD. Notice healthy appear clams other than the mantle at the affected area. The retraction of the irritated mantle curve upward.

Here is @outerbank Derasa that was treated with FWD. The clam appears healthy other than the area of mantle affected. The retraction curve upward.

This is immediate (a few days) post treatment

6 weeks post treatment

 

[Madison Reef]

That was when we were talking about other invertebrates like filter clam anemones and snails and the likes. I was able to clear my tank by just treating Tridacna clams. I never keep a Hippopus. I can confidently say that the PMD pathogen does not affect snails and filtering, non-photosynthetic clams. I would not confidently say Hippopus is in that group.

Thank you so much for clarification! Sorry for my stupid brain, sigh.

This photo was taken four days after arrival while ramping up the lights in the QT.

Taken today in DT. You can see the same spot is having the issue. No shell growth (for about a month) in DT.

 

[OrionN]

It does not look like PMD to me. He may be getting more light than what he used to. Did he have any growth prior to getting to your tank? Do you have other clams? are they growing? Are your corals growing?

 

[Madison Reef]

It does not look like PMD to me. He may be getting more light than what he used to. Did he have any growth prior to getting to your tank? Do you have other clams? are they growing? Are your corals growing?

The new clam did not have any growth when it came. It's been a month in the DT and the shell looks the same. I have another Maxima on bare bottom. Not all my corals are growing but most acros are.

 

[xjiang7]

How long do you suggest "clam free period" for DT? Should I at least try to separate them? Would it be helpful? I do have another (second) QT that is currently used for pods which can be easily turned into a invert/coral QT (the new clam in QT 1 and the old clam in QT 2 separately). Even if the pathogens are unknown, would it be a good idea to treat them like we treat fish with, say, bacterial infection? (of course I do not know what is causing the issue but at least it's better to give it a try rather than watch it suffering) I just can't handle watching the old clam that I cared and loved slowly perish.

Your help is much appreciated. Thank you!

I will upload the photo of both clams tonight, at the end of photoperiod. Thank you for your willingness to help!

What affected my clam is not necessarily PMD. I have had that which are especially common with maxima clams. I have two tanks, one of them has a blue squamosa I have had for almost 4 years and have been healthy and growing. Typically I left it by itself and put other clams in the other tank, unless I see new growth on those clams.

I did not track the time when my other tank had been clamless after a clam die off. The last die off happened directly after I add one corcea clam from a vendor, which is actually a free gift. By that time I have one maxima (no shell growth but also no PMD) one corcea that has been growing and two dersa clams that have been growing very fast.

After I added the corcea clam, my dersas and corcea stopped growing and died slowly, espcially with dersas developed the hinge disease. However, the blue squamosa is none affected, and I don't think it harbored disease as it doesn't seem to reaffect new clams after a die off.

Clam death can happen from many causes not necessarily disease. I suggest to make sure your tank has the premium water quality and strong light, then add one cultured clam and start from there