live rock worm

[dgramsky]

Have a 60 gal. tank with 85 lbs. of live rock. Waiting for tank to cycle. One piece of rock came with a live crab which I think is good for the tank. My question is regarding the other night at appx. 0400 hrs. in the morning I was looking in the tank with a flashlight and spotted something the diameter of a toothpick and appeared to be brown in color stretched from one rock to another when the light hit him he retracted back into the rock. Seems he only comes out when its dark. Is this (worm?) a concern before I put fish into the tank?
Thanks in Advance,

 

[essexboy73]

Hitchhicker...good thing imo...could be a bristle worm or a peanut worm??
The crab on the other hand could be a bad thing...i had one in my tank when i first set it up..i was just happy as a lark to see something alive in there!! Then one morning i found a snail shell without the snail near the hole that the crab was living in...needless to say he got boiled!! The one i had was some kind of a mithrax species...he had black tipped claws...just keep an eye on him!