Crocea needs help. Bleaching?... and a hole?

[Mish]

Hi,

Quick list of events:
I rearanged some rock and move the clam down in the tank. Watched closely and he seemed fine with the move. About 4 months after the move I noticed some whitish spots. I then moved him back up to his original placement in the tank, and I have seen no change in the spots. He has been in this location for about 2 months. Now It looks like I can see a hole through the center of him. He is still attached to the rock, and I can not see a hole if I pick him up and look at the bottom of him. I also noticed that it looks like the tissue between the 2 halfs of the shell has gone white where it used to be the same color as the mantle. Is there anything I can do?

As of last week water prams were:
sg 1.023
Cal 410
Alk 12
Nitrates 5ppm

Tank is a 75gal with T5 lighting 4 52watt bulbs.

Here are a couple of pics, but not sure the pictures really show the problem. Also, he sometimes appaers to be gaping, but not always.





Thanks,
Mish

[JetCat USA]

looks like a normal fold of the mantel not a hole and the other pics look normal as well. your salinity is low and your Alk is high, both not good for a calm.

[a4twenty]

Originally posted by Mish
Also, he sometimes appaers to be gaping, but not always.

crocea's are known to hold their incurrent siphon open more than other clams.

Originally posted by Mish
Now It looks like I can see a hole through the center of him. He is still attached to the rock, and I can not see a hole if I pick him up and look at the bottom of him.

that hole you are seeing is normal. you are looking through the incurrent siphon and right back out through the byssal opening. when you pick him up to look from the bottom he probably closes up making the the byssal opening much smaller.

Originally posted by Mish
I rearanged some rock and move the clam down in the tank. Watched closely and he seemed fine with the move. About 4 months after the move I noticed some whitish spots. I then moved him back up to his original placement in the tank, and I have seen no change in the spots. He has been in this location for about 2 months.

bleaching is usually caused by lack of light ( or to much to fast ). from what i see in you photo the area in question is underneath a fold in the mantle and therefore not receiving any light when the clam is fully extended. if the mantle is not receiving any light it cannot support the zooxanthellae algae and will appear white. ( i have this in several of my larger clams ) if there is something more that i have missed, perhaps you could post a top down picture

Originally posted by Mish
I also noticed that it looks like the tissue between the 2 halfs of the shell has gone white where it used to be the same color as the mantle.

as i explained above if the tissue is receiving no light there will be no color. this portion of the clam you have circled looks perfectly normal.


HTH