Sphyrna lewini (Scalloped hammerhead)

A large hammerhead with a notch at the centre of head, 1st dorsal moderately high, 2nd dorsal and pelvic fins low. Colour light grey or bronzy to reddish above, white below, lower lobe of caudal fin with dark blotch.

Sphyrna mokarran (Great hammerhead)

A very large hammerhead with a notch at the centre of head, 1st dorsal very high and curved, 2nd dorsal and pelvic fins high and with deeply concave rear margins. Colour light grey or grey-brown above, white below, fins unmarked

Sphyrna zygaena (Smooth hammerhead)

A large hammerhead without a notch at the centre of head, 1st dorsal moderately high, 2nd dorsal and pelvic fins low. Colour olive grey or dark grey above white below.