A rather unique billfish, with a flattened bill formed from an elongated upper jaw. It has a single high dorsal fin (crescent-shaped) and one keel on each side in front of the tail fin. Color of back is variable, including shades of brown to grayish-blue to black above, shading to a lighter color below. This species lacks scales, teeth, and pelvic fins. Body shape is elongate and somewhat compressed.