It's hard to distinguish fry, but Piranhas generally have spots, and the jaws are what really gives it away, besides the way they just attacked the filet I tossed in for them..
Glad they are doing good! It sure exciting watching them, but also every morning and you turn on the light, there is a chance for something to be wrong!
Yeah Mal, I freaked out earlier I couldn't find the fifth, and was running around freaking out. Then he decided to come out from under the filter and it was like phew. I find myself counting them every time I walk by the tank.