The family Pomatomidae contains only one member, the bluefish Pomatomus saltatrix. The bluefish closely resembles the pompano family with its two dorsal fins and one anal fin. The ventral fins are well forward of the dorsals, located underneath the pectorals. Blues have a broad, forked caudal fin, and the lower jaw protrudes slightly beyond the upper jaw. The upper and lower jaws are lined with a series of stout, conical canine teeth. Although the bluefish visually resembles the pompano, ichthyologists believe that its skeletal characteristics relate it more closely with the sea bass family.
Bluefish are seagreen colored above with a silvery belly below. The pectorals are marked with a black blotch at the base. Bluefish can grow to a maximum of about three and one-half feet. The heaviest American bluefish weighed twenty-seven pounds, caught off Nantucket in 1903. They run somewhat larger off the African coast, where one forty-five pound bluefish has been recorded.
They are generally oceanic in nature, being found either inshore or offshore. They are creatures of warm water, preferring water temperatures not less than sixty degrees Fahrenheit. Blues appear on the eastern United States coast as seasonal migrants. They feed on a variety of polycheates, crustaceans and fish prey.
The earliest reported commercial catch off southern Massachusetts was in late May. Early in the season they feed offshore on the bottom. Later they are seen harrying other fish near the surface. Blues come inshore and tend to turn up in bays or estuaries in the warm months of July and August.
Bluefish spawn from late spring to the middle of August. The larvae are similar to mackerel larvae in that they have large blue eyes and large teeth. Bluefish fry have been found inshore during the summer in both the Gulf of Maine and south of Cape Cod. These catches are presumably products of that season's spawning. The age at which the bluefish reaches sexual maturity is undetermined.
During the winter months the bluefish seem to disappear north of the Carolinas. Their destination is the subject of some debate. Members of the northern population may move offshore to warmer water near the outer edge of the continental shelf. It is also thought that they may migrate far to the south. The recapture of a tagged fish was recorded off the coast of Cuba in January 1939. The fish had been tagged off New York the previous August. There seems to be no interchange taking place between the populations on either side of the Atlantic.
The diet of the bluefish consists of a variety of polycheates, crustaceans and fish prey. Opossum shrimp Neomysis americana, sand shrimp Crargon septemspinosa, grass shrimp Palaemonetes vulgaris, bay anchovy Anchoa mitchilli, stripped killfish Fundulus majalis, and Atlantic silver-side Menidia menidia dominate in terms of biomass and frequency.
Bluefish are also food for many other organisms. Blues are the primary prey for the shortfin mako Isurus oxyrinchus, an important sportfish in southern Florida. The relatively recent presence of bluefish in Maine waters has generated a good deal of excitement on the part of our saltwater recreational fishing community.
Richard P. Kelley
For more information:
- Bigelow, H.B., and W.C. Schroeder. Fishes of the Gulf of Maine, 1953
- Friedland, K.D., G.C. Garman, A.J. Bejda, A.L. Studholme and B. Olta. Trans. Am Fish Soc., 1988
- Ogilvy, C.S. and A.B. Dubois. Journal of Experimental Biology, 1981
- Stillwell, C.E. and N.E. Kohler. Canadian Journal of Fisheries and Aquatic Science, 1982