Need ID Help...please....

[Red Sea Purple Tang]

The pic was taken this morning with all the lights off, sorry for the quality. Attached to the clam on the left side is the "sand tube" in question. I'm starting to lose some of my clams, and this "sand tube" is the new comer in each case. Any ideas?

http://home.att.net/~cheezheads/S_RCthing.JPG

[lil'salty]

i cant tell in the pick
how many have you lost dude
clean it off and look for pyrmalied snails i think thats how you spell it