insect in my tank ?

I have a 20 g. tank with 2 guppies, 15 freshwater shrimp and an apple snail..

my shrimp have been breeding some..
Today I found a small 6 legged thing 1/4 inch long.. that looks like a small dragon fly with no wings..

Is this a young shrimp ? It has no "rear legs" or fins on the tail..
it curls it's tail up over it's back like a scorpion does..

I have not added any new fish or plants in over 2 months.. the only thing new to the tank is a new power head..

anyone have a guess..?? I'm in Indiana.. the tank is indoors.. I don't think it could be a wild insect..



|]}80 The Herbivorous ate well; their food- it didn't run.