This species is redescribed and is distinguished from congeners by the absence of keel as the only diagnostic character; with lower number of dorsal spines 9 (vs. 10 in P. pungitius); head rounded with a concave snout (specimens longer than 35 mm SL) accentuating the impression of fleshy lips; dorsal spines 8-9; anal soft rays 7-11; scutes on the caudal peduncle 0-4; pectoral-fin rays 10-11. Colouration: body generally bright green with dark tints, covered by blackish blotches, which are absent on the pectoral and abdominal regions (Ref. 125067).