Sailfish

The sailfish is a large, fast-swimming pelagic fish belonging to the billfish family Istiophoridae. It is best known for its spectacular, oversized dorsal fin, which resembles a sail and can be raised or lowered at will, along with a long, spear-like upper jaw. Sailfish are found in warm, open ocean waters throughout the world's tropical and subtropical seas, typically near the surface. They are among the fastest fish in the ocean, capable of short bursts of very high speed while hunting. Sailfish are popular as game fish and are generally considered of Least Concern by conservation assessments, though localized population declines have been noted due to fishing pressure. They play a role as fast-moving predators of small schooling fish near the ocean surface.

Identifying features of the sailfish:

• Long, rounded, spear-like upper jaw (bill), shorter than that of marlins relative to body
• Extremely tall, sail-like first dorsal fin, often taller than the body is deep
• Vivid cobalt-blue to grey-blue back with a silvery-white belly
• Faint rows of pale blue vertical bars or spots along the flanks
• Slender, laterally compressed, streamlined body

Adults reach roughly 1.5-3.4 m. The oversized dorsal sail immediately distinguishes sailfish from marlins and spearfish, which have much lower, less dramatic dorsal fins.

Sailfish inhabit warm, open ocean surface waters throughout tropical and subtropical regions of the Atlantic, Pacific, and Indian Oceans, generally in water temperatures above about 21°C. They are epipelagic, staying mostly within the upper 100 m of the water column, often near current edges, drop-offs, and areas of high prey concentration close to shore or around offshore structure. Sailfish undertake seasonal migrations tracking warm water and baitfish movements, and are more coastal than some other billfish, frequently encountered within sight of land along productive current systems.

Sailfish are highly active, fast-swimming predators known for cooperative hunting behavior, in which small groups corral and slash through schools of sardines, anchovies, and other baitfish using their bills, then pick off stunned individuals. Their dorsal sail can be raised to herd prey or lowered to reduce drag while swimming at speed. Sailfish are among the fastest fish in the ocean over short bursts. They spawn in warm offshore waters, releasing large numbers of pelagic eggs that drift and hatch in open water, with no parental care afterward. As fast pelagic predators, they help control populations of small schooling baitfish near the surface.