Something eating my torch and frogspawn

[molybdenumman]

In the past few months I have found that my otherwise healthy (very full) torch and frogspawn are being eaten??? The heads are alright, but the skeleton itself is diminishing (it kinda looks like a beaver has attacked the skeleton). I don't think its the fish, they would more likely go after the heads themselves. Has anyone ever seen this attack on the base of the coral? Any advice would be greatly appreciated.

Thanks,

Dan