nope, a balck neon has a white stripe, is a much more condensed body, and has red eyes..... mine has a black stripe an elongated body, upturned mouth and black eyes. i really dont think its a tetra, its much too stretched looking........
I'd say its a type of rasbora, or a bait minnow, did it come with the feeder rosies? there are a lot of minnow type fish that are raised commercially i'd take peak at some of those. i cant think of a species off the top of my head to start with.
It looks like it could it possibly be a Notropis heterodon, otherwise known here as, a Blackchin Shiner. You could take a look at this website, it has a pretty good picture (drawn) and compare it to your fish. http://fish.dnr.cornell.edu/nyfish/Cyprinidae/blackchin_shiner.html
over looked the rasbora family, went through the fishbase tetra entrues with no luck, deffiently a rasbora tho just finished going through those too. so ive narrowed it down to pretty much this one of 15 possibles, they are almost identical, but thast enuff for me, so great i have some kind of rasbora, i like him tho, certainly wont see it in neone elses tank