What type of bug is this?

So I was at my uncles house which is built beside a man-made lake where they stock fish such as trout. At night when my brothers and I went to see if we could spot some fish we placed the light of the flashlight into the lake only to notice little white bugs swimming around underneath the water, they were also swimming towards the surface for the light. They looked as if to have tails that drooped down below them and squiggled as well as they had four sets of claws (If I remember correctly) they kind of looked like crayfish claws. They were a very white maybe even a little transparent in colour. Anyone know what these might be?