ID? Staten Island Zoo - Unknown fish in fire-bellied toad exhibit

I believe these are Guppies (Poecilia reticulata)

That isn't what I thought guppies looked like

@TinoPup These are wild types, so much different than the bright colors that you would see in the pet trade. The larger one on the left is a female, because she's large with dull colors. The little guy on the right is a male. He's obviously much smaller and has more color. I could be a little bit off and they may be a similar species, but I'm pretty confident that they're Guppies.

@red river hog That's pretty neat, thanks for explaining!