|Family overview: Gars are primitive, ancient bony fish. Their ancestors date back more than 100 million years, as found in fossil records. In Pennsylvania, there are currently two gar species, the spotted (Lepisosteus oculatus) and the longnose (Lepisosteus osseus). At one time the shortnose gar was reported to be in the Pennsylvania portion of the Ohio River and in Lake Erie, but it has not been seen there in many years.
The spotted gar is found along the Gulf of Mexico, the Mississippi watershed, and lower Great Lakes. In Pennsylvania it lives mostly in and around Presque Isle Bay.
The longnose gar ranges widely through the Mississippi River watershed and lower Great Lakes. It is also found along the Atlantic Coast north to New Jersey. In Pennsylvania, it has been reported from scattered locations including Lake Erie, and the Allegheny and Ohio River watersheds. It has also been reported to be in the extreme southern portion of the Susquehanna River watershed. Never abundant, the longnose gar’s primary Pennsylvania haunt is the shallow, weedy waters of Presque Isle Bay in Lake Erie.
One oddity of the gar is its tolerance of low oxygen conditions. Gars have a swim bladder that connects to the throat by an open tube. When hard-pressed for oxygen in the water, gars can go to the surface and gulp air into the swim bladder, which then acts as a lung. The genus name “Lepisosteus” means “bony-scaled.”
Identification: The gar has a long, relatively thin-looking, cylindrical body that is “armored” with large, thick, diamond-shaped scales. Its beaklike or swordlike snout is filled with fine, sharp teeth. The single dorsal fin and the anal fin are located far back toward the tail.
The spotted gar is usually olive-green on its back and silvery-white on the belly. There are large, roundish dark spots on the top and sides of the head, and on the upper part of the body. The fins have dark spots and may display orange tints. The spotted gar grows almost to four feet long.
Longnose gar are grayish to olive-green on the back and white on the belly. They may have dark spots or blotches on their fins and especially toward the rear along their sides. The fins may show yellow or orange tints. They can grow to about 50 inches long.
Life history: Longnose gar adults live in lakes or sluggish pools and backwaters in rivers. They spawn in the spring, in the vegetated shallows of lakes, or they may migrate upstream to find a gravel bottom. Males mature in three to four years. Females mature a year or so later. No nest is built. Females may spawn with several males over the long spawning season. Up to 30,000 tiny dark eggs are released by each female. The eggs stick to underwater objects and plants. The eggs, which are poisonous to humans and other mammals, take six to eight days to hatch. Then the young gars attach themselves, by means of a suction disk at the tip of the snout, to something submerged. There they await the absorption of the yolk sac. Young longnose gars grow fast, nearly to two feet the first year. They may live to be 20 years old.
Spotted gars also spawn in the spring, with large groups of males and females appearing over riffles and in the shallows along lake shores. They make no nest for the eggs, but the gravel is cleaned by their spawning activity. They also spawn over underwater vegetation. The spotted gar grows more slowly than the longnose.
Gars are voracious carnivores, preying on other fish. Their hunting tactic is to lie in wait for prey to move close, or they may stalk it slowly. Then they rush in and slash their sharp-toothed “beak” from side to side, killing or injuring the target fish. The prey is then grabbed crosswise in the gar’s teeth and maneuvered in the jaws to be swallowed headfirst. Gars also occasionally feed on crustaceans. Gars are sometimes seen on sunny days, apparently basking, just beneath the water’s surface.