I purchased 4 of these a few weeks back. One of the 4 is huge, about twice the size of the others. 3 of them are about 1-1.5 inches long and the big one is like 3-3.25 with lonngg antenna. i am starting to debate whether is an amano. On top of that, i have observed this shrimp with the moon lighting on and its semi aggressive towards any thing that comes close. especially around feeding time. it hides out and it appears that this shrimp tries to grab what passes by. I bought 12 cardinals a week ago and i can only see 9. I am thinking this shrimp is taking them out at night considering they are half the size of the stalking shrimp. Has anyone experienced this or can relate. Does this sound normal for an amano.