pretty sure it's a rosy barb from the body shape and spot by the tail, they often have a yellowish tinge to them although i';ve never seen one quite this yellow, however if it's been selectivley bred to produce the high fin i wouldn't be surprised at selective breeding for colouring either
thanx. just found out about the white tip tetra, is like a cross between the two but silver instead of rose. they and the angel was the one one stand up to the black widow