Not a flying fox, Also not any of the pencil fish as they are characins.
My gues is that it the orangefin barb (Barbus eutania) that gets to just under 4"
IMO it looks like a Lemon Fin Barb, I had a few; They start off small and cute like that but get huge.... at 8" long it was about 3.5" from belly to dorsal....
Yea there's no way it can be a flying fox, i'd recognize one if i saw one. I googled up the sci. name Barbus eutania and nothing came up. Is there any way I can find more pix of them?