Crocea and byssal gland

[Pineapple House]

I first bought a T. crocea in January. I placed it upon the rockwork, and within a day it was fully attached to the rock. 8 1/2 months later, the crocea falls off the rockwork onto the sandbed. I placed it back onto the rockwork, to find that 3 days later the clam fell off the rockwork onto the sandbed. I again placed it in the exact same area it has been for the past 9 months, and it has again fallen off in less than 48 hours. Now, within the past 9 months, it's grown almost an inch in length and is constantly producing a new white shell (new growth).

I'm curious why it's not attaching to the area which it has been attached to for over 8 1/2 months. I've never changed anything in the past 9 months, including current. I do see the byssal gland searching around the rockwork to find a location, but it never seems to attach. Is this just a mere size issue (the clam is outgrowing its old location)? If this was the case, would I have to move it somewhere else? Or, is this a byssal issue? Maybe it's somehow damaged (which I doubt, as I can veiw it searching around the rock)?

Thanks,
Graham

PS. Here's a picture of the clam when I got it:
http://community.webshots.com/photo/72382296/72382547WNXOJX

Here's an updated picture of the clam:
http://community.webshots.com/s/image3/0/78/39/74807839zQtIlv_ph.jpg

As you can see, the clam is on a type of ledge. Could the clam be outgrowing this ledge?

 

[Project Reef]

Graham have you gone mad? lol

Didn't you move the crocea from the rockwork and place it on the sandbed yourself because it was taking up valuable real estate while on the rocks??

http://reefcentral.com/forums/showthread.php?s=&threadid=257796&highlight=crocea

If you put the crocea on a big shell on the sand bed, then just let it be. It should attach again, just don't keep moving it or touching it.

 

[Pineapple House]

Graham have you gone mad? lol

Didn't you move the crocea from the rockwork and place it on the sandbed yourself because it was taking up valuable real estate while on the rocks??

http://reefcentral.com/forums/showthread.php?s=&threadid=257796&highlight=crocea

If you put the crocea on a big shell on the sand bed, then just let it be. It should attach again, just don't keep moving it or touching it.

Yes, it was on the sandbed. Unfortunatly, it wasn't showing good mantel extention while on the sandbed (shell), so I moved it back onto the rockwork a day later.

Graham

 

[Project Reef]

The reason it's not showing good extension on the sand bed right now is because you just moved it from a location which it was happy and attached. Once you, especially for croceas, move a clam that was attached, to a different location, then it usually takes a few weeks for the clam to achieve full extension of the mantle. I would place the clam back on the sand (on top of the sea-shell) and give it a good 3 weeks to establish itself again.

 

[OrionN]

Once you cut the byssal threads, the clam may loose the whole bussal bunddle and regrowth a new one. This is alrming but OK. This maybe what happened when you move the clam from the rock down to the sand. Crocea require very high light. IMO, when I have a clam happy where it is, I leave it be. I break a coral and move it before I move a clam.
Minh