We have both Hickory And American Shad in the St. John's river in Florida. They are both anadromous spawning in rivers. The young Shad make their way back to the ocean to mature and return to spawn in 4 years. All the Shad that spawn in the St. John's die after spawning I think because of water temperature. They make good forage for all kind of wildlife both the young Shad and the dead spawned out fish. Fish that spawn in rivers north of the cape fear river can return to spawn the following year. I have caught American Shad to 6lbs. In the Susquehanna river, the state record is 8lb. You can tell the difference between Hickory and Whites (American) by the mouth, Hickory have an under bite, lower jaw extends beyond the upper jaw, White Shad the jaw comes together even.
Most fishermen around here troll for them but I like to cast jigs. The best day I had on the Susquehanna I caught and release 110 White Shad on another day I caught and release 300 Hickorys, could have been more........lost count