It is without question a member of the family Lebiasinidae which includes the Subfamily Pyrrhulininae. It could possibly be a species in the genus Pyrrhulina but I suspect Colin is closer with the genus Copella. The fish is obviously under severe stress and colours are not reliable, so I won't go further. "Splashing Tetra" is one common name for a species or two in this genus and this might well be one of them.
They are characins and thus must have a group; males can be feisty so more than the often-suggesteed "six" is best, I like to go with 7-11 depending upon space. They tend to remain close to the surface. Some can get a bit nippy of any fish venturing into their space, but the damage done is usually mild and not a concern. But it would not be wise to have them in with permanent surface fish like hatchetfish for example, or some of the very closely related pencilfiish (genus Nannostomus, also the Family Lebasinidae, Subfamily Pyrrhulininae).