Reef Fish

Oriental Sweetlips

Plectorhinchus vittatus · Bony fish — family Haemulidae (grunts and sweetlips)

Adult oriental sweetlips have perfected standing still in public. Schools of a few dozen hover in tight formation under table corals and overhangs through the day, thick lips and painted stripes all facing the current, barely finning — an arrangement photographers structure whole dives around, especially in the Maldives. They disperse at night to root crustaceans and worms out of the sand. The juveniles seem like a different animal entirely: blotched brown-and-white clowns that swim in exaggerated, flopping loops, a performance widely interpreted as mimicry of toxic flatworms, advertising unpalatability before the fish has size on its side. Day schools tolerate a slow, level approach to within a body length; rush them and the formation dissolves over the reef edge. The family name is earned — disturbed fish grunt audibly by grinding pharyngeal teeth.