Sweepers

Scientific name : Pempherididae

The family of Pempherididae, or sweepers, contains approximately 26 species divided into two genera: Parapriacanthus and Pempheris.

They are small fishes, with maximum lengths shifting between 8 and 30 centimetres. The body is extremely compressed, sometimes similar to the one of hatchetfishes, with one short dorsal fin, with origin before middle of body, and one long anal fin; the eyes are round and big, the mouth is strongly oblique. Swim bladder is present in all but one species (Pempheris poeyi). Some species possess luminescent organs.
Coloration is generally subdued, some species are extremely translucent.

They live in tropical marine shallow waters, aggregate in caves or in shady reefs by day and disperse to feed on zooplankton at night.