Does anyone know what kind of fish Mahi-Mahi is?

I've heard that Mahi-Mahi is the Hawaiian name for dolphin (the fish NOT the marine mammal!), also known as Dorado. Most restaurants use the name Mahi-mahi rather than dolphin, so as not to have any confusion with the marine mammal of the same name.
Is this true? I finally found a fish I enjoy eating and I find out it may be Flipper!
