Ok so here's the deal: I bought 5 ghost shrimps in a little sealed bag whcih was in cold water but I've read that they live in tropical tanks so I thought they would be fine. I let them float in the warm water in their cold bag for about 20 minutes to let them adjust to the temperature and put 2 in with the 2 male platys and Slurp the plec, and 2 shrimps in with the other 2 female and baby platy's with an otocinclus. My brother and I watched them all evening to make sure no biting was going on but when we woke up all 5 were dead. There are no marks or limbs missing - it seems they just keeled over. Its very sad because they were SOO cool to watch swimming around. Does anyone have any ideas what could have caused it?