Crocea clam mantle receding with mucus

I've had this Crocea clam for ~3 months, but over the past 3 weeks I've noticed folds and a dramatic recession in the clams mantle. These pictures were taken yesterday when I noticed long strands of mucus from under the mantle, and today the clam refuses to even open up. All the water parameters are nominal and I am currently running 178W MH w/ actinics in my 30g tank.

I've checked for pyramid snails at night and have not seen a single one and the only tank mates are two docile clowns.

Any ideas on what is going on or how to save my crocea?

 

Google Pinched Mantel Disease. And please list parameters.

 

Sorry, here are the parameters:

Temperature: 79
PH:8.4
Ammonia:0
Nitrite:0
Nitrate:<5
Salinity:1.024
Calcium: 450

From what I understand, if it is Pinched Mantle Disease, it's a death sentence for the clam? Is a FWD even worth while?

 

From my experience with it, a FW bath is hit and miss at this stage, miss being it quickens the clams demise.

Are you running any GFO or other media?

Also way is the clam at the bottom of the tank? It's hard to give Crocea too much light, are you acclimating it to the light? Unless it's a swallow tank, the clam might do better up higher in the rock work.

 

No, I'm not running any GFO (hadn't heard of it until now) but it's something I now plan on getting to help control phosphates. The media I currently have is the standard media balls that come with the Eheim canister filters. I did let it acclimate to the lighting when I first got it (slowly increasing the exposure hour by hour on a daily basis) and it seemed to thrive. Although I do have a "tall" tank and it is on the bottom of the tank.

So which would you suggest as the best first step: FW dip or relocation? I have never attempted to move it from it's new home as I've heard their byssal glands are easily damaged if not handled correctly.

Also, thanks for helping me out!

 

I don't see any issue with bleaching/color so I don't think I would be inclined to add stress by changing the location/lighting. The fact that it is holding itself closed vs. gaping open is a good sign that it still has energy and thus some hope for recovery. It's hard to make a diagnosis from just a couple of photos, but it does appear to be pinched mantel (PMS) to me. Based on what I can see, if it was mine I think I would perform a 1.009 dip. A hypo-salinity dip below 1.009 will give the same benefits as straight FW, but it's easier to match params this way (pH in particular). PMS is a 99.9% death sentence if not treated...however dipping has a very good success rate if you catch it soon enough. It looks like it is attached to a smaller piece of rock...if you choose to dip/move the clam I would suggest leaving on the rock and just move both together.

 

Ok, so I'll try the 1.009 dip this evening and get back to you guys. However, this is my first FW dip and I have no Idea how long to leave it. Also, should I just dilute the tank water with RO water to get the appropriate SG? Additionally, should I quarantine the clam afterward and prepare for the worst?

 

You want the FW bath to be at the same temp and pH as your display water. Believe or not 10-15 minutes. It will look stressed afterwards, if it comes around it usually takes a day or two.

QT will serve no purpose now IMO.

 

Agreed...temp and pH need to be as close to your tank water as possible to reduce stress to the animal. That's the advantage of doing the hypo vs. straight RO...it's hard to get the pH right in RO lot's of times. I generally go 30mins when I treat for PMS. As mentioned you may not see any immediate improvement...it maybe hours or days before you see a marked improvement...and most likely it will take several dips over the course of several weeks to completely turn the PMS around. I also agree there is no benefit to QT...I would put the clam right back in the same spot it was in after the dip.

 

Update:
So after the freshwater (1.008) dip the clam has been looking much better, losing many of the folds and opening up all the way. However, today it appears that it again is beginning to show PMD symptoms. So my question is how often could/should I do a dip to help my crocea recover?