Anterior nostril a short tube with simple cirrus on posterior rim; posterior end of maxilla of adult males produced as a thin flexible lamina that usually extends beyond posterior margin of opercle; spinous dorsal fin with black spot encircled by broad white ring; adult males with inner lining of maxilla and adjacent membranes with prominent black stripe (stripe usually absent or light brown and poorly developed in females; buccal pigmentation consisting of a large dark area widely surrounding esophageal opening, including medial area between upper pharyngeal tooth patches; caudal vertebrae typically 20 (Ref. 26893).