I'm not sure the turtles were snacking on it when I found it.
Could it have been in the spawning process and been hurt?
Possibly. If it's a female, then it looks like she dropped her eggs already. I've never seen Males with really swollen bellies during spawning. Spawning stresses the fish, and sometimes fish croak for reasons unknown to us "after the fact". I know it's upsetting to have your prized fish go belly up, no matter how small, but I look at it as a fact of life, even we do the best that we can to prevent it. From hatching to reaching adulthood, look at how many fish don't make it.......
