There are three species of thresher sharks all characterized by the unmistakably elongated upper lobes of their tail fin. This one, the pelagic thresh

- Image ID: PEC17E

There are three species of thresher sharks all characterized by the unmistakably elongated upper lobes of their tail fin. This one, the pelagic thresh

David Fleetham / Alamy Stock Photo

Image ID: PEC17E