White marlin are mid-sized billfish with a bill that is round in cross section, and distinctly forked caudal fin. Their body structure is designed for fast swimming with a long, streamlined appearance. The length of K. albida is measured from the lower jaw to the fork of the tail (lower-jaw fork length; LJFL). The largest white marlin reported was 2. 8 m (9. 2 ft) LJFL and weighed over 82 kg (180. 8 lb). The coloring of white marlin is used as countershading, with a dark blue dorsal side and a dirty white ventral side. Though all white marlin have the same coloring pattern, they are sexually dimorphic, with the females usually larger. One of the most noticeable features of white marlin is the dorsal fin, which extends along the majority of the dorsal portion of its body. The dorsal fin consists of typically 28 to 46 rays. These rays make up a fin tall and rounded in the anterior, but quickly levels off and then decreases as it extends to the posterior. Behind the large primary dorsal fin is the secondary dorsal fin, which is made up of five to six rays. White marlin have a set of similar pectoral fins and pelvic fins. These two sets of fin are rounded and wide at the tip. They also have two anal fins which can be used for identification between species. The lateral line on this species is prominent, with a hump above the pectoral fin and extends the length of the fish toward the caudal fin.