It was surreal and other worldly to me while swimming underground in crystal cold waters surrounded by fibrous tree roots hanging down from high above. How did these fish get in here?
Given a good tropical storm these get shaken up, scattered about, float to the surface, and get picked up by water spouts, waves, and other events that can carry them into the air and then at the mercy of the winds and sleeting rain movements .. some of which will shed into inland sinkholes, etc.
Further, much of the Southern North American and Central American land form is crossed by limestone and and underground river systems that are fed by water above ground; where water flows eggs can follow.