ok so after hours of peeking and sneeking around looking into the 28 i have finally foound something alive in there. it only comes out at night. it sucks in as soon as light hits it.it kinda looked like a bristle worm shape, without and bristles, but it was black with a small white tip. then about an inch away from the end it had 2 white rings around it. the part i could see sticking out was about 4 inches long, didnt get a real good look because it sucked back in very fast. and whats weird is that the rock was in transit for 3 days with no water in it at all, the outside surface looked almost like reefbones when i got it so there wasnt much water inside if that helps any. so if you know of any black and white worm looking things let me know what they are so i can find a pic and check it out! thanks again.