Pomatomus saltatrix
Ancho
(Also: Blue fish; Bluefish; Choppers; Elf; Fatback; Greenfish; Horsemackerel; Jumbos; Marine piranha; Razorbacks; Salmon bluefish; Shad; Skipjack; Skipmackerel; Snap mackerel; Snapping mackerel; Tailor; Tailor run)

Bluefish are found in all oceanic and coastal waters except the eastern and northwest Pacific. The adults can be found in estuaries and brackish water, but are most common in clean, high-energy waters, such as surf beaches and rock headlands (Agbayani 2001).

Smaller bluefish live nearly year-round in estuaries and bays along the coasts. As they mature, they begin annual migrations. As the size of the bluefish increases, the distance they migrate also increases. They can tolerate water temperatures as low as 14°C, and can maintain a body temperature up to 40°C above the temperature of the surroundings. These coastal fish will sometimes enter brackish water, where they can tolerate a salinity concentration as low as 7 parts per thousand (Meyer; Bachand 1994).

Adult P. saltatrix reach an average length of 30 cm but can grow as large as 120 cm. Coloration is greenish-blue to dark blue above giving way to a silvery white on the sides and below. They are covered in relatively small scales, have a straight lateral line, a forked tail, and dorsal and anal fins. Bluefish have an extended, down-turned lower jaw, with both jaws being lined with extremely sharp, conical teeth. (Bachand, 1994; Temple, 1999)

Bluefish have no external characteristics that can be used to distinguish males from females. However, males mature at an earlier age but their eventual size is not an indicator of gender. During their second year, bluefish reach sexual maturity. The females extrude between 0.6 and 1.4 million eggs in spurts as they migrate along the coasts. Males then spread their milt and fertilization occurs. Depending on water temperature, the free-floating, oil-filled eggs can hatch within 44 to 48 hours of fertilization. The newly hatched bluefish then migrate into estuaries and bays until they reach a weight of approximately 3 lbs. (Bachand 1994; Meyer).

Pomatomus saltatrix are constantly moving, as they travel in schools that can extend 6 to 8 km in length. As the schools move through the water, they will attack other schools of fish, destroying large numbers of excess prey. Each year, beginning in January, bluefish begin their annual migration northward. The cause for this migration is unknown, but it is speculated that it is due to seasonal changes in light intensity and the length of the day (Bachand 1994; Agbayani, 2001).

Bluefish are strictly carnivorous, eating squid, shrimp, crabs, and fish, such as herring, atlantic mackeral, menhaden, spot, butterfish, and mullet. They are visual feeders that hunt in schools and will attack anything that moves or slightly resembles food. Bluefish will often first bite the tail off their prey, will then consume the food, will regurgitate, and will again eat (Bachand 1994; Meyer).

Bluefish are economically important as both a sportfish and as a food. The bluefish's aggressive feeding habits and the fight it puts up makes it a very popular sportfish. Each year, about 55 million kilograms of bluefish are caught by anglers. In the United States, bluefish account for about 1% of the commercial fishery landings, but over the past 20 years, the catch was tripled (Manooch 2001; Species bluefish).

Pomatomus saltatrix can increase and decrease the amount of air in their swim bladders faster than any other known species of fish (Bachand 1994).