mucous coming out of crocea clams?

[chwattscaw]

I have two clams, they have been in the tank for over a year now....doing well, always open, and look to be growing.

However they frequently secrete a thready mucous.

What is this? Is it normal, and if not what can I do to get it to stop, or help the clam rid itself of the stuff?

Is it a matter of flow?

 

[epon]

My croceas do this in response to a little bit of red wire algae touching their mantle on the edge of the shell. I'm curious about the thready mucous too.