Dorado have compressed bodies and a single long-based dorsal fin extending from the head almost to the tail. Mature males have prominent foreheads protruding well above the body proper. Females have a rounded head. Their caudal fins and anal fins are sharply concave. They are distinguished by dazzling colors – golden on the sides, and bright blues and greens on the sides and back. The pectoral fins of the mahi-mahi are iridescent blue. The flank is broad and golden. Out of the water, the fish often change color (giving rise to their Spanish name, dorado, “golden”), going through several hues before finally fading to a muted yellow-grey upon death.