The freshwater whipray (Himantura chaophraya)? Its range is over most of south east Asia and northern Australia. Like other rays, its side fins basically merge into it's flat-shaped body.
Carnegiella marthae (the black-winged hatchet fish) is a small fish with wing-like fins up on its body; their preferred habitat is flowing water; naturally found in Central and South America.
Many lampreys are also said to have "winglike" fins, which come into use most of all when they are swimming upriver to spawn.
I think there must be more fish with wing-like fins. I did find the African butterfly fish ( Pantodon buchholzi, an exotic kept in freshwater home aquariums); these fish really can sort of fly over large water surfaces, but they prefer stagnant rather than moving water (lakes rather than rivers).
Carnegiella marthae (the black-winged hatchet fish) is a small fish with wing-like fins up on its body; their preferred habitat is flowing water; naturally found in Central and South America.
Many lampreys are also said to have "winglike" fins, which come into use most of all when they are swimming upriver to spawn.
I think there must be more fish with wing-like fins. I did find the African butterfly fish ( Pantodon buchholzi, an exotic kept in freshwater home aquariums); these fish really can sort of fly over large water surfaces, but they prefer stagnant rather than moving water (lakes rather than rivers).