Striped Marlin, or Nairagi in Japanese, can be distinguished from its cousin, the blue marlin, by its distinct blue bands across the width of its body. It is also lighter and has a more slender bill. Marlins are a highly migratory fish living at the top of the food chain in the tropical and subtropical regions of the Pacific and Indian Oceans. It is a member of a larger family known as billfish, which get their name from their upper jaw that extends to form a spear. Because of its immense size, marlin is prized as a sports fish. The most distinguishing characteristic is its high, pointed first dorsal fin, which normally equals or exceeds the greatest body depth. Even in the largest specimens this fin is at least equal to 90 percent of the body depth. Like the dorsal fin, the anal and pectoral fins are pointed. They are also flat and movable and can easily be folded flush against the sides, even after death. The sides are very compressed. The lateral line is straight, single and clearly visible. The back is steely blue fading to bluish silver on the upper flanks and white below the lateral line. There are a number of iridescent blue spots on the fins and pale blue or lavender vertical stripes on the sides. These may or may not be prominent, but they are normally more prominent than those of other marlins, and they persist after death, which is not always true on other marlins.Marlin are highly migratory and, therefore, not a lot is known about their spawning periods and behaviors. Dorsal spines (total): 0; Dorsal soft rays (total): 42-48; Anal spines: 0; Anal soft rays: 18 - 24. Body elongated and compressed; upper jaw produced into a robust and medium sized beak; two dorsal fins, the height of the first greater than the greatest depth, short anteriorly, taller in the middle, then becoming shorter posteriorly; pectoral fins falcate and flexible, with 18 to 22 rays; body densely covered by small, embedded scales with 1 or 2 bluntish points; back dark blue; belly silvery; membrane of first dorsal fin blue black without dark spots; flanks with about 20 bluish stripes. Blue-black above and silvery white below, with about 15 rows of cobalt-colored stripes; 1st dorsal fin dark blue; other fins dark brown, sometimes with a tinge of dark blue; anal fin bases with a tinge of silvery white.