The endemic Lake Malaŵi cichlid genus Otopharynx is increased from 14 species to 20 by the description of six new species collected from inshore sandy or intermediate rocky/sandy areas or trawled in depths to 59 m. Otopharynx alpha is distinguished from congeners by its unique melanin pattern with suprapectoral spot discrete but supraanal and precaudal spots connected to form a stripe, and by its distinctively shaped pharyngeal bone with numerous small, crowded teeth. Otopharynx mumboensis, thought to be endemic to Mumbo Island, is separated from most congeners by a suprapectoral spot placed entirely below the upper lateral line, and from all others by the combination of 13 gill rakers, pharyngeal bone with posterior margin nearly straight, crowns of all pharyngeal teeth in the median columns broadened and flattened, head length 30.9–32.2% SL, body depth 35.5–36.1% SL, and lower jaw 35.7–36.2% HL. Otopharynx styrax has a more elongate body (depth 24.3–28.6% SL) than any congener. Otopharynx aletes can be diagnosed by the combination of a suprapectoral spot overlapping the upper lateral line, seven or eight vertical bars below the dorsal-fin base, 10 or 11 gill rakers, 34–36 scales in the lateral line, lower pharyngeal bone with molariform posteromedian teeth, and caudal peduncle length 1.6–2.0 times its depth. Otopharynx panniculus is diagnosed by the combination of a prominent square suprapectoral spot spanning subdorsal bars 3 to 4, no dorsal midline spots, 13–15 gill rakers, 31–33 scales in the lateral line, 15 or 16 dorsal-fin spines, absence of a lacrimal notch, and slightly enlarged teeth in the median columns of the lower pharyngeal bone. Otopharynx peridodekamost closely resembles O. panniculus and shares the loss of the lacrimal notch, but has 34–35 scales in the lateral line and 11–13 gill rakers. Photographs of living or freshly collected specimens of five of the new species are provided.
Lake Malaŵi Trawling Survey