Blackeye Thicklip Wrasse

The blackeye thicklip wrasse (Hemigymnus melapterus) belongs to the wrasse family and originates from the Indo-Pacific region.

This medium-sized fish can reach up to 50 cm in length, having a high, relatively compressed body, a large head, and thick-lipped mouth parts. Body coloration changes with age. Young fish have a ground color with yellow-green transverse stripes, a wide white diagonal stripe behind the gill cover, an orange caudal fin, and a greenish-gray front. Mature females have green coloration behind the diagonal line, with black edges on the scales. A complex tangle of pink lines, highlighted by turquoise, may be found from the tip of the nose to the head. Fully developed males have emerald-green stripes behind each scale, a blue edge around the eyes, and green tips of the nose and head with pink patterns highlighted by turquoise.

This species inhabits tropical and subtropical waters of the Indo-Pacific, from the eastern coast of Africa including the Red Sea, to Polynesia, and from New Caledonia to southern Japan. It prefers areas with corals, coral debris, sandy areas, outer reef slopes, and drop-offs, often found at depths over 40 meters. Juveniles, however, tend to be more secretive, seeking shelter in branching corals.

The blackeye thicklip wrasse usually leads a solitary lifestyle or lives in small groups. As a benthic predator, it mainly feeds on small marine invertebrates such as crustaceans, mollusks, worms, and echinoderms, caught on or in the substrate. In addition to searching for food on coral branches, it can scoop up mouthfuls of sand, sifting out food and then expelling the sand through the gill covers. Like most wrasse species, it exhibits protogynous hermaphroditism, meaning individuals start life as females with the possibility of later transforming into males.