The spotted gar (Lepisosteus oculatus) is a primitive freshwater fish of the family Lepisosteidae, native to North America from the Lake Erie and southern Lake Michigan drainages south through the Mississippi River basin to Gulf Slope drainages, from lower Apalachicola River in Florida to Nueces River in Texas, USA. It has a profusion of dark spots on its body, head, and fins. Spotted gar are long and have an elongated mouth with many teeth used to eat other fish and crustaceans. They grow to 0.61–0.91 metres (2–3 ft) in length and weigh 1.8–2.7 kilograms (4–6 lb) on average, making it the smallest of the gars. The name Lepisosteus is Greek for "bony scale". Habitat for spotted gar is clear pools of shallow water in creeks, rivers, and lakes.
The spotted gar is a part of the gar family (Lepisosteidae). They are notable for being one of the few extant fish species with ganoid scales. They have been known to hybridize with (and look similar to) Florida gar. It occurs in quiet, clear pools and backwaters of lowland creeks, small to large rivers, oxbow lakes, swamps, and sloughs. It occasionally enters brackish waters. The fish is a voracious predator, feeding on various kinds of fishes and crustaceans. The lifespan for L. oculatus varies between males and females. The maximum lifespan for a gar is 18 years. Males mature at the age of two or three, whereas females mature at three or four years old. Females on average are known to be larger and live longer than the males. Females also have less annual mortality rates.
The spotted gar is native to North America and its current range is from southern Ontario to the west from the Nueces River in Texas east to the northern coast of the Gulf of Mexico and southeast to the lower Apalachicola River in Florida. The gar population is small in the north and is being threatened in Lake Erie by the destruction of their habitat and pollution. The gar is more common in the southern waters like the Mississippi River basin from southern Minnesota to Alabama and western Florida. Historical records indicate the spotted gar resided in the Thames and Sydenham Rivers in Ontario, Canada. Also, the fish was once common in Illinois in the Green and Illinois Rivers to the swamps in Union County; though sporadic, the population has dwindled in these water systems because of the loss of specific habitat they need to live, clear pools with aquatic vegetation.