Fish Identification Photos: Sailfish, Istiophorus platypterus: The Sailfish is characterized by its enormous sail-like first dorsal fin which is much taller than the width of its body, runs almost the length of its body, and has many small black dots more common at the anterior end. The coloration of the Sailfish is dark blue dorsally and white underneath. The Sailfish's upper jaw extends into a long rounded bill which has a circular cross-section and is twice as long as the lower jaw.

The Sailfish has two keels at the caudal base and two anal and two dorsal fins with the second anal and the second dorsal fins being short and concave mirror images. The Sailfish's fins are generally black, but the anal fin base is white. The Sailfish has long pectoral fins and extremely long pelvic fins that are twice as long as the pectoral fins. Its sides have 20 rows of vertical bars that are composed of light blue round spots. The lateral line is readily visible.

The Sailfish is one of the smaller members of the Xiphiidae family and the Istiopherinae or Billfish Sub-family which includes billfishes, marlins, sailfishes, and swordfishes. It is the subject of some controversy, with some individuals believing that the Pacific Sailfish is different from the Atlantic Sailfish, Istiophorus albicans.

The Sailfish is a tropical and temperate water species normally found above the thermal incline in the first 100 feet of the water column in both oceanic and inshore waters. It prefers water temperatures of 21 to 28 degrees Centigrade. The females release 4.5 million eggs annually. The Sailfish feeds on halfbeaks, mackerel, mullet, needlefish, small tuna, cephalopods and crustaceans. The Sailfish is not easy to confuse with other species due to its enormous dorsal fin. The Sailfish is a highly prized targeted species of sport anglers.

In Mexico, the Sailfish is found along the Pacific side of the Baja California peninsula, in the lower 90 percent of the Sea of Cortez, along the coast of the mainland through to Guatemala, and around all of the oceanic islands. It is reported to reach a maximum length of 11 feet, and the I.F.G.A. All Tackle Record, as of 2004, stood at 220 pounds.

Sailfish, Istiophorus platypterus: Caught at Cabo San Lucas, Baja California Sur, Mexico. Photo courtesy Fly Hooker Sportfishing. Sailfish, Istiophorus platypterus: Photo courtesy Larry Hahn. Sailfish, Istiophorus platypterus: Photo courtesy Larry Hahn. Sailfish, Istiophorus platypterus: A sailfish caught by kayak angler Dennis Spike of Coastal Kayak Fishing, at Rancho Leonero, East Cape, Baja California Sur, Mexico. Photo courtesy Tony Mullins, who assisted in the release. Photo by Marsha Felton. Sailfish, Istiophorus platypterus: This sailfish identified as hypomelanistic, by Dr. Russell Nelson, was caught at Manzanillo, Colima, Mexico, on November 2, 2003 by a commercial longline boat: "This is a very unusual and magnificent sailfish, but it is not a real 'albino' form. Note the dark splotches on the head and dorsal fin, as well as the eye. This fish is "hypo melanistic," meaning it has an extraordinary lack of melanin, the coloring pigment. In a true albino there would be no dark coloring on any of the body and the eye would be pink from a lack of any coloring in the cornea, pupil and lens." Photo courtesy Luis F.A. Koyama.