We ordered 2 urchins. Due to some misunderstandings, we were not at home to sign for the package and had to pick them up today instead of yesterday. One urchin lost its spines and died. The other has its spines and I can see little tentacles sticking out and moving, but he is floating at the surface of the water. Does anybody have any idea what is going on? We put a couple of pieces of rock in the acclimation bucket in hopes that he'd be able to grab onto it--no luck so far. I can't find anything anywhere about why he is floating! Any help would be much appreciated. Thanks!