Dorsal spines (total): 0; Dorsal soft rays (total): 10 - 15; Anal spines: 0; Anal soft rays: 13 - 19; Vertebrae: 63 - 72. Distinguished by the presence of large black spots on the back and on both lobes of the caudal fin; the young have no parr marks (Ref. 27547). Body fusiform, streamlined, somewhat laterally compressed; moderately, deeper in breeding males (Ref. 1998). Mouth terminal, normally very little oblique but greatly deformed in breeding males, with lower jaw enlarged, turned up at tip, mouth unable to close (Ref. 1998). Adipose fin large; pelvic fins with axillary process (Ref. 27547). Fish in the sea are steel blue to blue-green on the back, silver on the sides and white on the belly; large oval spots present on the back, adipose fin and both lobes of the caudal fin (Ref. 27547). Breeding males become dark on the back, red with brownish green blotches on the sides; breeding females are similar but less distinctly colored (Ref. 27547).