Bluefish eat everything

Bluefish are truly the cannibals of the sea. They eat anything and seem to take special delight in eating each other. It makes you wonder why they are still around — how they get close enough to spawn with each other before biting their paramour in half.

Scientifically known as Pomatomus saltatrix, it shares a peculiarity with cobia and tripletail. Each fish is the only member of its family, an oddity in the fish world. The first part of its name, Pomatomus is derived from the Greek words for “cover” and “portion,” presumably in some reference to its gill covers.

The word saltatrix is pure Latin and interprets as “dancing girl.” That word in turn is derived from saltor, which means “jump” or “dance,” maybe because of its jumping and hard fighting abilities when hooked.

As for its common name — perhaps “greenfish” would be more appropriate, since its body color is steely, mint green, fading to silver below. Besides its large golden eye, it has few other distinguishing features. It is generically fish-shaped and its fins are typical fish fins and in all the right places.

What it does have that sets it apart from almost all other fish, is a mouth of razor-sharp cutting teeth that it uses to cut chunks of flesh from its prey. Most other fish species (exceptions are sharks and piranha) use their teeth to grab the fish they are going to eat and swallow them whole.

They are noted for being among the most ferocious and bloodthirsty fish in the seas, leaving in their wake a trail of dead and mangled fish. Bluefish tend to school by size. Smaller fish will often be found very near shorelines, along beaches and even in brackish bays. Larger fish will be found further offshore.

In the Gulf of Mexico, bluefish seldom grow over 10 pounds, unlike on the Atlantic Coast, where the world record of 31 pounds, 12 ounces was set. Louisiana’s record fish of 21.88 pounds was caught by Steve Van Every in 1982. Not a single bluefish has been added to the state’s top 10 list in 30 years — since 1984, when a 15.25-pounder was placed in the No. 5 spot.

Bluefish have a huge natural range, being found in temperate and subtropical waters around the world except for the northern and central Pacific Ocean. Eighty percent of the world’s catch is made from the Atlantic coast of the U.S., Brazil and Turkey. They are quite common off of Africa, where fish as large as 45 pounds have been reported, an intimidating size, considering their ferocity.

The bluefish is one of the most popular sport fish in the U.S. Atlantic states, where their populations expand and contract on a 10-year cycle. They are so popular there that recreational fishermen overfished them to record low numbers by 1996. A stringent fisheries management plan was put in place to restore their stocks.

Gulf of Mexico bluefish are of an entirely different stock than Atlantic fish. Louisiana fishermen largely ignore bluefish, or curse them as a nuisance when they chop fishing tackle to bits or devour everything but the heads of more desirable fish on their hooks.

The stock difference may account for the difference in growth rates between Atlantic and gulf coast bluefish. A study done in the late 1970s and early 1980s compared growth rates between gulf (Louisiana and Florida) bluefish and Atlantic bluefish from Florida to South Carolina.

At each age up to age 4 gulf bluefish grew faster than Atlantic bluefish. They averaged 14 inches at age 1, 17 inches at age 2, 25 inches at age 3, and 28 inches at age 4. After that, growth almost stopped for Gulf of Mexico fish and fish 6, 7 and 8 years old averaged the same size at about 30 inches long. Females and males grow at about the same rate. Maximum lifespan for bluefish is about 9 years old.

Gulf of Mexico bluefish are not considered to be strongly migratory, unlike those on the Atlantic Coast. There, bluefish are found off of Florida during the winter months. By April they have disappeared, heading north, reaching Massachusetts by June. Some fish move as far north as Nova Scotia, Canada. By October, bluefish have left their northern hunting grounds and are on their way back to the south.

Bluefish swim constantly. At high speeds they practice ram-jet ventilation, opening their mouths to let oxygenated water flow over their gills by the force of their swimming alone. At lower swimming speeds, they pump water over their gills with their gill covers. They are not well adapted for low-oxygen conditions.

Their life of constant activity allows them, like tunas, to keep their body temperatures warmer than the water in which they are swimming. Bluefish will travel in schools 3 to 5 miles long, constantly hunting bait species. They find their prey primarily with their eyes, but will respond to smell as well.

On the Atlantic Coast, schools of bluefish over 20 pounds will crowd bait species into shallow surf waters and rip through them, cutting and tearing the living fish as they go. They will often bite the tails off their prey, consume them, regurgitate (throw up) what they have eaten and then eat more. Their attacks will churn the water like a washing machine and sometimes called “bluefish blitzes.”

They are warm-water fish, intolerant of temperatures much below 50°F for any length of time. Above 95°F, they quickly die. Spawning occurs at water temperatures of 64 to 77°F, and in gulf it takes place in April and then again in October-November.

Near sundown, a female will swim on its side extruding eggs while it swims. She is attended by several males, swimming slightly faster than the female, who discharge sperm. One million eggs have been counted from a 23-inch female. Bluefish become mature at age 2.

In one Louisiana study, fish made up over 90 percent of bluefish diets, with drums, herrings and jacks comprising 78 percent of the volume of food eaten. The most common drum family member eaten was the Atlantic croaker. The most common herrings were menhaden (pogies) and Spanish sardines. The most common jack was the cigar minnow.

Shrimp, squid and crabs also appeared on the menu. Most of the shrimp were eaten in the spring and were eaten by smaller fish. Some bluefish had sand in their stomachs. The presence of sand and, in other areas, sea grasses in their stomachs indicates that they feed at the bottom at least some of the time.

Some scientists have also noted that bluefish seem to have a distinct preference for eating other bluefish.

Besides humans, sharks, swordfish, wahoo, and tuna feed on bluefish. One study showed bluefish to be the main food item (77.5 percent) of shortfin mako sharks. On the Atlantic coast, bluefish ranked fourth in number and third in volume of all food items found in swordfish stomachs.

In spite of being relished by humans on the Atlantic coast, bluefish are seldom eaten in Louisiana. The flesh is dark and quite fishy-tasting. If there was ever a doubt to the accuracy of the information found on the Internet’s Wikipedia, they list the fish as “good eating.”

About Jerald Horst 959 Articles
Jerald Horst is a retired Louisiana State University professor of fisheries. He is an active writer, book author and outdoorsman.