They don’t spawn until they are around 10 years old and can live several decades. On the average the males live up to about 36 years, the females up to 50 years. They can live up to 58 years, grow up to 10 feet long, and weigh up to 300 or more pounds. The young eat insects and larval fish while the adults eat crustaceans, birds, fish, mammals, rats, and turtles. Their roe, or fish eggs, are poisonous, not only to animals, but also to humans.
While they are native to the Mississippi basin, they extend into Missouri, Ohio, and Texas as well. Populations for gar are decreasing as they require very exacting conditions to spawn successfully. The water temperatures must exceed 68 degrees. Those specific conditions are not always easy to obtain. Levees that have been built have walled them off from their spawning waters.
Another reason for the reduced population is that they have been extensively fished. They were once a favorite target for bow fisherman. Plus, in the past, when gar were caught accidentally, fishermen would sometimes break their beaks as they considered them a dangerous fish to both swimmers and game fish. So the gar would starve to death, and this too reduced the population.
It seems the only redeeming quality, from a conservationist biologist’s standpoint, is that the gar eat silver carp. This is an invasive species that is multiplying. Eating silver carp to reduce those populations seems to be the gar’s claim to fame. They are also being considered in the in the fight against another invasive species called the snakehead fish.