Indeed, spotted eagle rays are stingrays, just one of the many species
of stingrays, which also includes southern rays, bullnose rays,
roughtail rays, cownose rays, marbled rays, etc. etc. All have barbs
on their tails that they use to defend themselves from predators,
never for aggression or predation.

There are rays that don't have barbs -- mantas and butterfly rays for
example, but they are rays as opposed to skates, the difference being
that all rays give live birth, while all skates lay eggs. And of
course all skates and rays are elasmobranchs, meaning they have
cartilagenous skeletons. All sharks also are elasmobranchs.

Now the bonus question: What kind of animal is a sawfish?

g