Perciformes (Perciformes) sailfish family (Istiophoridae) several species of long-nosed large marine fish collectively. The body is elongated, with a long dorsal fin and an extended kiss in the form of a long dart gun. Drift in the global sea surface. Carnivorous, mainly feeding on other fish. Its meat is delicious and very popular with anglers. There are many fish called marlin, but there are four recognized species, namely, blue, black, striped and white marlin. The blue marlin (Makaira nigricans) has a worldwide distribution, and can be as large as 450 kilograms (1,000 pounds) or more, with a dark blue body, a silvery-white belly, and often with light-colored vertical stripes. The black marlin (M. indica or Istiompax indicus) is similar in size to the blue marlin or larger, and is known to reach over 700 kg (1,500 lb). Indo-Pacific species; dorsal side of body blue or blue-gray, ventral side pale; unusual in having straight pectoral fins that intersect the body at an acute angle, making it difficult to flatten them against the side of the body without external force. The striped marlin (M. audax or Tetrapterus audax) is another Indo-Pacific marlin, with the upper part of the body light blue, the lower part white, with gray vertical stripes, and its weight generally does not exceed 125 kg. The white marlin (M. albida or T. albidus), which only occurs in the Atlantic Ocean, has a bluish-green body with a grayish belly and grayish vertical stripes on the sides of the body, and has a maximum weight of about 45 kilograms.
The marlin is a large fish famously depicted in Hemingway's novel The Old Man and the Sea.
It has a long upper jaw like the sailfish, and swims at high speeds across the ocean. Its dorsal fin extends to the back of its body, and its ventral fins become filamentous, which distinguishes it from the swordfish.
The marlin caught on the hook splashes violently and its jumps are spectacular.
It is very touching that the male marlin always lets the female marlin feed first. Ernest Hemingway described it in his novel The Old Man and the Sea: The male fish always let the female fish feed the first!