Peacock Grouper

Cephalopholis argus, commonly known as the peacock hind, roi, bluespotted grouper, and celestial grouper, is a species of marine fish belonging to the subfamily Epinephelinae, which is a part of the family Serranidae. This species can be found in the Indo-Pacific region and has various roles, including being commercially fished, an invasive species, and sometimes found in aquariums. Its species name, argus, originates from its resemblance to the "hundred staring eyes" of the mythological monster Argus, who was the shepherd of the goddess Hera.

The peacock hind is a medium-sized fish, growing up to 60 centimeters (24 in) in length. Juveniles have a dark brown coloration with numerous small, dark-edged iridescent blue spots. As they mature, larger individuals might develop four to six lighter vertical bars on the back half of their bodies.

This widely distributed species inhabits warm waters, ranging from the 🌊 Red Sea to 🇿🇦 South Africa and east to 🇵🇫 French Polynesia and the Pitcairn group. It can also be found in northern 🇦🇺 Australia, Lord Howe Island, 🇯🇵 Japan, and has been introduced to the Hawaiian Islands. While it utilizes various habitats, it prefers exposed reef fronts up to depths of 40 meters.

When hunting, the peacock hind lies motionless on the ocean floor before making a sudden surge forward to capture juvenile surgeonfish and crustaceans. It may also employ other strategies, such as cooperating with predators like octopuses or eels or camouflage themselves within a school of surgeonfish. In some cases, multiple individuals work together to harass an eel into flushing out prey for them. In the 🌊 Red Sea, hunting primarily occurs during the morning and evening.

These groupers typically reside on coral heads and retreat when startled. In the 🌊 Red Sea, males establish and defend harems consisting of 2-6 females within territories that can span up to 0.5 acres (0.20 ha). Each female defends her portion of the territory from the others. The male visits each female daily, signaling his approach by raising his dorsal fin. The females respond by emerging from hiding, raising their own dorsal fins, and changing to a lighter color. They swim together, rubbing flanks before the male departs until the next day. Territorial disputes between males might involve "color fights," where they darken their colors and repeatedly switch the lighting of their bars. The loser typically becomes pale and retreats, while a draw may result in mutual attacks.

In 🇫🇲 Micronesia, spawning typically occurs territorially at dusk. During courtship, both sexes darken their coloration, leaving only a white keyhole-shaped patch at the center of their bodies.