Guppies

[Gracelovespixie]

Why are some of my baby fry born lighter almost clear and the others really dark almost black or dark brown ?

 

[Delapool]

I've had that even with both parents (and probably grandparents) being black mollies. Sometimes they darken up over time. I assume it is mother nature throwing a bit of randomness in there. From ages back in school they talked about black moths used to stand out on trees and thus not many / bad news to be a black moth but started to really thrive with the industrial age in the UK as the soot made the trees black as well (and it was bad news to be a light coloured moth as these still occurred).