The Asian sheephead wrasse (Semicossyphus reticulatus) is one of the largest and most recognizable reef fish in the temperate coastal waters of Korea, Japan, and China. This species is famous for its massive head, pronounced forehead bump, and drooping lips, especially in mature males. These features, paired with a human-like expression, make it a favorite subject among divers and photographers. Asian sheephead wrasses inhabit rocky reefs and kelp forests, often patrolling their territories alone or appearing near coral structures. Like many wrasses, they are protogynous hermaphrodites, meaning they start life as females and transition to males as they grow older—typically becoming more dominant and physically dramatic in the process.
These fish feed on hard-shelled invertebrates like crabs, sea urchins, and mollusks, helping to regulate benthic populations and maintain ecosystem balance. They are slow, deliberate swimmers and can often be seen closely observing divers, adding to their charismatic presence. Whether encountered along Japan’s Izu Peninsula or Korea’s southern coast, the Asian sheephead wrasse offers a striking and memorable encounter with one of the reef’s most expressive and ecologically important fish.