What Type Of Fry

[livelifelow]

Is there a way to distinguish the type of fry while they or young or do you need to wait until they have grown a bit?  My mom's tank has both guppies and balloon mollies and Christmas morning we had fry.  Personally I think they are from the molly since she was hiding in a cave, then staying down near the gravel, but she hadn't really squared off yet.

 

[noobgamers]

if theyre baloon mollies there will be noticible difference but they may be hybrids from my experience guppys are much more prolififc breeders and mollie fry are usually 10mm while guppys are about 5mm (the sizes are approximations)

 

[bluesword23516]

They will only be hybrids if you only have male guppies and female mollies, or female guppies and male mollies.  If there are males of their species in the tank they will only mate with them.  Look at the females and see if one is smaller.  Its been a few days so it probably wont look any different.  If there are any coloring on the fry they are mollies.  Guppies don't show any color until about 3 weeks old and its only on the tail. At about four weeks their top fin will gain some color.

 

[Donya]

They will only be hybrids if you only have male guppies and female mollies, or female guppies and male mollies.  If there are males of their species in the tank they will only mate with them.  

 
This is perhaps the most common scenario but hybridization is not impossible in mixed environments. Once in the past I had hybrid fry (male guppy with female molly) from a tank containing males and females of both species.

 

[livelifelow]

I'm thinking they're from the balloon, they look to be closer to 10mm and their stomachs seem to be rounding a bit.  I don't think they're hybrids, we actually bought the fish on a Sunday and they were born the following Wednesday.  The balloons were in with black mollies, so I could imagine a breeding there, but the guppies were just with other guppies.  One of the fry is actually darker than the others, so I wouldn't be surprised if they're mollies.  I wish I could look at the female for a comparison but the female balloon was dead the next day. 
 
Thank you all for the help in possibly identifying them.

 

[fish48]

Thay don't cross that easily  The chances of it happening is almost 0,
Many fish keepers see a few fry from a mixed community tank and because they have mollies and guppies kept together and then assume they have crossed. it is more complicated than just keeping a few species together and hoping that they will cross –breed.you really need to start with virgin stock Even then there's no guarantee that thay will breed