Gar

Scientific Name: Lepisosteus oculatus (Spotted Gar); Lepisosteus osseus (Longnose Gar); Lepisosteus platostomus (Shortnose Gar); and Atractosteus spatula (Alligator Gar); Lepisosteus platyrhincus (Florida Gar); Atractosteus tristoechus (Cuban Gar); Tropical Gar (Atractosteus tropicus

Common Names: Gar, Garpike

Gar fish are interesting for a lot of reasons. Probably one of the most obvious is their appearance. They have long, bony jaws that resemble spears. These help them prey on other fish and crustaceans and are equipped with rows of sharp teeth to rip food apart.

Gars’ neat physiology comes from their ancestry. They are members of an ancient order of ray-finned fish that has existed since the late Cretaceous period, hundreds of millions of years ago, when dinosaurs still walked the Earth.

In addition to their elongated mouths, Gars have long, cylindrical-shaped bodies. Spotted Gars can grow up to 3 feet long, while Alligator Gars can get much bigger, sometimes passing 9 feet in length. Typical color schemes for Gar include brown or olive-colored upper bodies, white or tan lower bodies, and spots. They also have thick, diamond-shaped (ganoid) scales all over their bodies.

Because of their bones and tough scales, as well as their tendency to prey on sportfish, some anglers consider Gar to be “trash fish,” meaning that they don’t consider them worth catching. But many others still try to fish for Gar, and prize the fish for their fighting abilities. Regardless, Gar play an important ecological role as apex predators in many of its native waterways.

Gar Interesting Facts

Gar are stalking predators who prefer to ambush their prey;
they are most threatened by habitat destruction;
Gar fish have swim bladders that they can fill with air to supplement gill-breathing in low-oxygen environments;
the fish are commonly described as “living fossils” due to their ancient ancestry;
and Alligator Gar fish have a second row of teeth in their upper jaws that they use to paralyze prey.

Gar Distribution

There are three species of Gar that live in the Great Lakes. These include Longnose, Shortnose and Spotted Gar. The Alligator Gar, which is the largest of the gar species, is more commonly found in the southern United States. This puts it nearby the Florida Gar, which can be found in Florida and Georgia.

Distribution of Spotted Gar in the continental United States. (Credit: U.S. Geological Survey)

The other two gar species, the Cuban Gar and Tropical Gar, are found outside of the United States. The Cuban fish inhabits waters in Western Cuba, while the Tropical Gar is found in freshwater areas from Mexico to Costa Rica.

Gar Biology

A 2013 study by scientists at the University of California investigated the structure and fracture resistance of Alligator Gar’s armored fish scales. Researchers describe the foundation of the scales as a “mineralized matrix and parallel arrays of tubules” containing collagen fibers. When the scales sustain attack, the collagen fibers beneath reinforce them to resist more damage. Full results of the study are published in the journal Acta Biomaterialia.

Researchers at the University of Southern Mississippi and the Texas Parks and Wildlife Department studied the possibility that Alligator Gar could hybridize with Longnose and Spotted Gar in the wild. Their 2013 study came after evidence had been found in another investigation showing Alligator Gar would hybridize with Longnose Gar in captivity. Scientists found that hybridization between Alligator Gar and other Gar species does occur in natural habitats. Their results were presented at the 143rd annual meeting of the American Fisheries Society.

A 2015 investigation by researchers at the University of Cantabria, University of Messina and the Instituto per L’Ambiente Marino Costiero revealed the workings of the gas bladder in Spotted Gar. Scientists found the bladder was made of a combination of striated and smooth muscles, nerves and neuroepithelial cells, indicating that its function is highly regulated. The full results of their analysis can be found in the Journal of Morphology.

References Cited

Gar article by Daniel Kelly, Fondriest Environmental, June 2015

Gar

Gar Interesting Facts

Gar Distribution

Gar Biology

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