i have also heard that the smaller ones ship better but they are almost impossible to keep so i dont know where the information on their survival rate came from . i myself had good luck with them from 1" to 4" and it goes just like this . they come in and do pretty well for a few weeks and they may have hidden for a few days to begin with and then after i think all is well i find all of them dead on the gravel bed fat and in perfect physical shape .i have had many of them and once i gave up i have heard that they are very sensative to alk and or ph changes and need very stable conditions . so they should be put in a systen that is dosed by a doser not a human that will forget from time to time and have the paramiters shift around a bit . also after i gave up on the choati's i have hooked up drippers etc so i dont have to manually dose etc . i wish you the best good luck and merry christmas