Breeding takes place in spring when females, often accompanied by several males, attach their eggs to clumps of submerged vegetation.
After consuming their yolk sac, the young fish feed on insect larvae and small crustaceans, maturing at an age of about three years.
Similar to many Paleozoic and Mesozoic actinopterygians, their bodies are covered in rows of interlocking, rhomboidal ganoid scales that create an exceptionally protective, yet flexible armor around the fish.
Shortnose gar vary in color, changing from brown/olive green on the dorsal surface to yellow on the sides and white on the underbelly.
Gar gas bladders have the ability to function like a lung to extract and use oxygen from swallowed air in addition to regulating buoyancy.
Often accompanied by more than one male, females scatter large, yellowish-green eggs in quiet, shallow water among submerged vegetation or other underwater structures.
One exception is in Montana, where they are considered a fish of special concern due to restricted distribution and limited population sizes.