Chase Landry was supposed to be in a Louisiana court Monday for the start of his trial for opening fire on a boat on the bayou -- but he never showed, and the judge issued a warrant for his arrest.

We broke the story ... Chase was arrested last year after he shot at the boat while gator hunting. He insists he thought it was gonna crash into him, and that's why he fired. Chase's attorney was in court, and we've reached out to him to see if he knows why his client no-showed.

Our guess? He's out hunting something.