Insect and Spider Identification: Please help identify , 1 by jamiej87

jamiej87 wrote:
this bug was found swimming around in a feeder minnow tank at my work. It very well could have come in with a shipment, i've never seen anything like this around here. I live in the Chicago subs. It seems to be doing fine in the water, I don't know how long it was in the tank for, right now he's in a little container with a little water. He doesn't look like a water bug to me but it doesn't seem to hurt him at all. He is very cute tho! I don't just want to let him go he'll die outside now.