so not long ago my tank was crawling with stomatella snails. in my 37g i had at least 70 crawling about. then i started seeing my cleaner shrimp eating them. im not saying the shrimp killed them but it was def eating the bodies. now i see all the empty shells in the sand, teeny ones and the bigger ones too. i can't see any alive now. i haven't seen any hermits eating any so i don't think they were killed by the crabs. my params are good, 0 nitrates now in the tank... nothing else in the tank has died, all the other snails and inverts are doing just fine. what could have cause all of the stomatellas to die?