Pempheris bexillon, a new species of sweeper (Teleostei: Pempheridae) from the Western Indian Ocean.

Pempheris bexillon new species is described from the 129 mm SL holotype and 11 paratypes (119-141 mm SL) from the Comoro Islands. Twelve other specimens have been examined from the Agaléga Islands, Mascarene Islands, and Bassas da India (Madagascar). It is differentiated from other Pempheris by the following combination of characters: a yellow dorsal fin with a black, distal margin along its full length, broadest on anterior rays (pupil-diameter width) and gradually narrowing posteriorly, the last ray with only a black tip; large, deciduous cycloid scales on the flank; dark, oblong spot on the pectoral-fin base; anal fin with a dark margin; segmented anal-fin rays 38-45 (usually >40); lateral-line scales 56-65; and total gill rakers on the first arch 31-35; iris reddish-brown. Tables of standard meristic and color data for type material of all nominal species of cycloid-scaled Pempheris in the Indo-Pacific are provided.