Last night I saw what appeared to be a piece of detritus floating around on the face of the anemone, but it was moving in a direct up and down pattern. I continued to watch for awhile but couldn't spot it again. Then tonight my son noticed something running across the sand and luckily I was able to get a picture of it. Sorry it's so grainy but could anyone identify this creature? I have no idea where it came from as there isn't anything in the tank yet other than one scarlet skunk cleaner shrimp, multiple snails and crabs, one pom-pom crab and a green bubble tip anemone.

I could just imagine sandbed suddenly boiling up with some dreaded bug infestation.

