so I started my saltwater aquarium 2 weeks ago and I have three pieces of live rock. The second day the live rock was in there I saw a crap load of worms 2 big bristle worm. And a lot of little worm like things. All the little ones look they have died off but now I have noticed some other things living on it. Kind of a spitter web looking thing that hase tentacles on it that reach out in the sand . And what appears to maybe be a clam that has grown on one rock. Not really sure that it's a clam,lol. Can someone kinda give me an idea of what things can be living on or in my live rock?? Please help me identify what these might be.