Bit by a Fish

Fishing a couple nights ago out on lake Josephine. I had waded out to about knee height in the water and was taking in a few small sunfish. Then a large something tried to take me in. I feel this chomp on my ankle, and man I was out of that lake so fast I hardly remember what happened. Whatever it was actually broke the skin and left me with a 1/4" x 1" scrape just above my ankle. I've been in a lot of lakes and never had anything like this happen to me before.