The Longnose Gar's food source depends on the area they live in.  They primarily feed on smaller fish as adults.  When they're growing up, their diet consists of insects and small crustaceans.  Some of these organisms include catfish, copepods, mayflies, and sunfish. 

Longnose Gars are ambush predators.  They hunt during the night and day, but they prefer the night.  They lie in wait on the surface of the water pretending to be a piece or wood or dead vegetation.  They swim up to their prey by swimming sideways, further making them look like sticks.  They grab their prey sideways in the jaw and turn them so they get swallowed head first.

Video of Longnose Gar eating: