Sick clam expelling white stuff

[wwu123]

I've had two 4" crocea clams in my 50G aquarium for the past six months. The tank has been established for about a year. Up until this week both clams appeared to be healthy, and growing 1-2 new rows of scutes.

But three days ago, one of the two began to gape and retract its mantle and has been on a rapid downward spiral. This morning I noticed a hole in the side as well; however, it did react quickly to light stimuolus several times. Tonight it started expelling milky white stuff with small bits of white tissue that fall apart easily; it's doing it from the exhalant as if coughing every minute or so.

It seems it is dying; should I remove it immediately lest it foul the tank?

Here is a photo:

 

[walkthedog]

Hard to tell from the photo. The retracted mantle is not a good sign. Also crocea clams enjoy being on the rock work more than in the sand. At least mine do. It could be spawning. It will release white stuff when it does that. If it is not attached to the sand you can move it and see if it does better. Is the hole on the side or at the end. At the end would be normal. Also if sand got into it; the clam mignt be trying to get it out. From the picture it looks far from dead or dieing. But it is hard to tell from the pic. Good luck hope it makes a recovery.

 

[moliken]

seems like something is bothering it. expelling?? a list of inhabitants might show something. retraction is worse than the expelling, imo

 

[wwu123]

It is hard to see in the photo, but there is a taco-shaped rock that cups both under the clam and on the right side about halfway up. The clam has been attached to the rock for the past six months, so it's not sitting in sand. I moved it yesterday, and was able to feel that the byssal threads were still attached to the rock, though the attachment felt a bit loose.

The hole is on the other side, don't know what the anatomy is called, but it's the inhalant side where there's a large width of tissue between the two shells before you get down to the foot. There's a lot of recession of tissue here and at the foot, whereas before the tissue went straight across to connect the shells before, now the tissue is a half-inch down.

The hole is not clearly visible this morning, it's light brownish in the center of the tissue, not sure if there's detritus or something plugging the hole, or that the clam is more closed up this morning. But overall it's closed rather than gaping, and did react once to movement.

Other tank inhabitants:
-two true percula clowns
-two blue-green chromis
-mandarin fish
-neon goby
-bangaii cardinal
-sand-sifting diamond goby (have not seen him drop sand more than an inch above the sandbed, never on top of the clam)
-yasha goby and tiger pistol shrimp
-peppermint shrimp
-pom-pom crab
-blue-legged hermits and cerith snails for cleanup crew

Never seen anyone harass or show interest in either clam, however, above this clam were candy-cane corals, the clam used to touch the three closest heads at full mantle extension, those three candy-cane heads were clearly irritated by the contact and have not expanded for over a month.

 

[wwu123]

Having seen some coral spawning in the wild before, I'm hopeful that the white milky stuff was indeed spawning. I just looked at two Youtube videos of crocea spawning, and they looked just like what I observed, with one of the two also expelling bits of tissue in the milky cloud. Also it happened after lights out, and was not happening during the day.

But even if it was spawning, there does seem to be something else going on with the mantle retraction and tissue recession. This clam was getting less light than my other one. Would the recession be symptomatic of slow starvation? I've moved him directly under the lights now.

 

[moliken]

the pompom, if a critter is a cause. does the sifter deposit sand on the clam mantle? mine does. don't worry about it in sand or not. maxis usually attach, but cert'ly not always.
about the "hole," that'd worry me. any chance for a shot of that for a better idea?

 

[wwu123]

Sorry this is the best shot I could get of the other side where the hole is, had to hold a flashlight to illuminate the area and have the camera zoomed all the way in:

I can't really see the hole right now, you'd have to be down from below looking up around the area below where the shells pinch closest together. But I think the tissue recession is visible, as is how brownish/dirty it is around that receded area.

 

[wwu123]

There's a bunch of distracting stuff in the foreground of the previous shot, so for orientation, here's a shot of the clam from the same angle I caught while photographing my Yasha/pistol pair, though it doesn't illuminate the tissue area.

The sick clam is the one to the left, the healthy clam is above.

 

[wwu123]

Though I saw one slight and slow response to light this morning, indicating its still alive, the mantle is completely limp and floppy. So without any flow through the inhalant and exhalant, nor any way to photosynthesize, there's no way for it to re-energize.

I'm going to remove it from the main tank pre-emptively, esp since my other clam seems to be sensing something and is now keeping tightly clamped up since the lights went on this morning....

EDIT: Moved the sick/dead clam to quarantine tank just for observation today so look for any signs of pests/critters that might have been the cause. Within a few minutes of removing it, my other clam opened back up to its normal state. Whew!

 

[moliken]

good luck. examine for pyr snails.

 

[wwu123]

I think it's dead, or at least doing a great job of playing dead.

Since I moved it to the QT tank, I got a better shot of the hole:

One reason it was hard to capture earlier is that it's not a clean round hole as if something had eaten through it. Rather its like something the diameter of a pencil punctured it, tearing a hole but leaving an attached flap that mostly fit back into the hole. About halfway around the hole is visible in the photo, the other halfway around is hard to tell because the flap of tissue is filling the hole.

I'm trying to remember if I may have caused a puncture while cleaning the tank. But highly unlikely, I had acan colonies around the clam and would have been hard to accidentally bump it from that angle...

The mantle and insides otherwise look fairly intact and no clear sign of anything having nibbled on it from the outside or inside.

(You can also see my red flatworm problem; although they would sit on the shell, they didn't crawl onto to mantle while the clam was alive.)

 

[moliken]

goner.