Any ideas?

[Wiggles24]

I know this isn't s great pic but I have had this guy for quite a while now n I feel bad cuz I really don't know what he is. I bought some blue finned killies a while back n he was sent to me as part of the group it was clear to begin with that he was different he is certainly not a blue finned Killie nor does he look like any killifish I have seen from what research I have done I am pretty sure he's s gambusia minnow. I really do feel bad even though he's kinda a jerk he just seems really lonely

 

[bettaowner]

That looks like a gambusia. Yeah they're pretty aggressive.

 

[Athaocity]

mosquito fish maybe?
by aggressive, if it is a mosquito fish, it is said.that they do eat their fry.

 

[bettaowner]

He's a livebearer for sure.

 

[tamtam]

That looks like a gambusia. Yeah they're pretty aggressive.

I do believe you are correct.