Pygmy Sweeper

Parapriacanthus ransonneti

The pygmy sweeper (Parapriacanthus ransonneti), also known as the golden sweeper, is a small fish in the family Pempheridae. Adults reach about 10 cm with a deep, compressed, translucent golden body and large eyes adapted for low-light conditions. This species inhabits coral reefs, caves, and overhangs at depths of 3-40 meters across the Indo-Pacific, from the Red Sea and East Africa to the western Pacific and Australia. During the day, pygmy sweepers aggregate in dense schools numbering hundreds to thousands inside caves, under ledges, and in shipwrecks, creating glowing golden clouds that are one of diving's most atmospheric sights. At night, they disperse to feed on zooplankton. Their translucent bodies catch and reflect ambient light in caves, creating a luminous, otherworldly effect that is a highlight of many tropical dive sites.