My First What is it Thread!

dbl · Jul 18, 2016

So I found this creature in the tank last night on a small piece of rock next to my Maxima clam. I've asked a couple of friends well versed in creature ID and it has them stumped. So I thought I'd post up here and see if anyone has any ideas. It has what appears to be a base/foot but that is not the part that was attached to the rock. The white stringy things are attached, and attached pretty well I might add. The pictures are a little blurry because I didn't turn the flow off, but I think you'll get the idea. The last picture is in a small container after it's removal.

Parameters are pretty solid as follows in case anyone cares:

pH 8.2
Salinity 1.026
Temp 79
Alk 7.9
Calc 420
Mag 1310
no3 1
po4 .05

Let me know what you think.

Lionfish Lair · Jul 18, 2016

Actually, I just took this picture elsewhere and they thought it was a clam's foot. I believe they are right.

Tahoe61 · Jul 18, 2016

Yes byssal threads of a Tridacna. If this clam fell then there might be serious damage to the foot of the clam and that is not good.

dbl · Jul 18, 2016

Interesting. The clam hasn't "fallen" that I'm aware of...ever. Here's what does happen to it on occasion. It will start to list/tilt to one side every once in a while. Something disturbs the sand around it's base and it will start to tilt to one side. The last time, which was at least a month ago, I propped it back up as I always do. I actually used that small piece of rock rubble and put it right up against the clam to sort of support it, if you will. So, not sure if this information helps or just adds confusion. By all indications, the clam is healthy and happy.

So are you saying this might be a piece of the maxima's foot?

EDIT: Should have added the Maxima's foot is actually attached to a different piece of rock and buried under the sand.

Tahoe61 · Jul 18, 2016

The item looks more dense than just byssal threads but I have seen that before. A clam with an injured foot is a dead clam typically.

Tridacna need a stable platform to attach to, propping them up seldom works long term.

Smaller and mid sized Maxima and Crocea attach to maintain an upright position, inability to attach can lead to stress, stress kills clams. Sometimes if the lighting is sufficient the sand bed is better placement.

dbl · Jul 18, 2016

Thanks so much for the help. A little history...I purchased the clam from a fellow reefer two years ago. It was attached to a piece of rock when introduced to my system. It is still attached to the same piece of rock and it sits on the sand bed in my tank. The rock is buried in the sand but the base of the clam is on top of the sand bed, if that makes any sense. The only picture I have at the moment is below...clam is circled in red on the bottom right. Hopefully, it will explain what I'm trying to say.

I guess my next question is...should I lift the clam up and see if I can see any damage to the foot and to make sure it is still attached to the original rock like I think it is? Or what is the next course of action in your opinion. I'd hate to loose it but I also don't want it going south and taking on collateral damage!

Tahoe61 · Jul 18, 2016

Ahh beautiful tank and clam.

Yes clams do attach to a platform when in the sand bed, the platform can be just beneath the surface of the sand. Placement looks really good where the clam is currently at. If that is just a dense ball of byssal threads from a clam that has been attached for long periods of time the clam was probably just re-positioning than it's all good, or the clam no longer needs the attachments as it's own weight now holds the clam upright, and based on the tank shot that looks likely.

No I would not disturb the clam to check the foot, there is nothing you could do any way. If the clam looks otherwise healthy I would leave it be.

Again nice tank, love that large hammer and the sps on top.