Could this be the creature eating my polyps?

[lil.guppy]

So my flower like polyps have been dissapearing like crazy but my zoanthids I have not noticed a problem.
I found this guy cruising around! He was a bout an inch long in the tank and got cut in half when I was taking him out so hes half the size and on his back in the picture.

 

[teresaq]

Thats just a stomatella (spelling) they are algea eatters
T

 

[lil.guppy]

poor little guy

 

[mr.clownfish]

i used to have a million of these little guys but they all suddenly disappeared