Darksome

It sort of looks like Heterandria formosa, the fins sort of throw me off though. I could be right, I could be wrong.

jmontee

It is a blue fin killifish. These fish are common in the breeding tanks here in florida nurseries. They will show up in big shipments of ghost shrimp too. I used to have a few of them but I got rid of them due to how aggressive they were with my shrimp.

Travis.808

Sorry to hijack your thread I thought it was a thread for identifying fish. Anyway I'm wondering if anyone knows the scientific name for bachardi's or where to get a breakdown of these fish. Also I think jmontee is correct, I did a search on blue fin killifish looks like the one.