What's going wrong here ?

[kuifjetintin]

Recently I bought several small tridacna... and most of them are not doing well.
What could be wrong ? They all look like this one, the mantel is retracted near the great syphon.
(sorry for my bad english)
Thanks!

http://www.freewebs.com/kuifjetintin/bevolking.htm

 

[mbbuna]

looks like pinched mantle,there are a lot of posts about it

 

[mbbuna]

read thiswww.reefcentral.com/forums/showthread.php?s=&threadid=554185

 

[kuifjetintin]

thanks! I'm on that post now and already practicing the advices.