About Hemigymnus melapterus (Bloch, 1791)
The half-and-half wrasse, Hemigymnus melapterus, is a medium-sized fish that can reach a maximum length of 50 cm. It has a tall, relatively flattened body, a large head, and a terminal mouth with thick lips. Its body coloration changes with age. Juvenile half-and-half wrasse have a greenish yellow base body color with yellow vertical stripes, a broad white diagonal band just behind the operculum, an orange caudal fin, and a greenish gray front of the body. Mature females are green behind the oblique line, with scales rimmed in black. A complex tangled pattern of pink lines with turquoise underlaying runs across the head from the top of the snout. Mature males in the terminal phase also have an emerald green stripe behind each scale and a blue rim around the eye; the top of the snout and entire head are green, with pink patterns highlighted in turquoise. This species is widespread across the tropical and subtropical waters of the Indo-Pacific, ranging from the eastern coast of Africa (including the Red Sea) to Polynesia, and from New Caledonia to southern Japan. It favors habitats with coral, coral rubble, and sand, including outer reef slopes and drop-offs, and occurs at depths down to at least 40 m. Juveniles are more secretive and always stay hidden in branching corals.
