Megalops atlanticus and Megalops cyprinoides, Atlantic and Indian-Pacific tarpon. The Atlantic ones get bigger and are much more rare in the hobby.
there is talk about the atlantic may actually have 2 sub species or strains. the one up by florida and there seems to be another that gets thicker and bigger down by french guiana. there they find a smaller skinnier bodied fish(florida strain) that gets long but not as heavy as the other style of tarpon. at the same size they see both the skinnier body and the thick body. one may be a subspecies. it could just be were the fish spawned and grew up, like north and south of french guiana and then when they congregate there you see the different class fish from the richer southern waters. not much research is being done on it now, but hopefully they will do some.