Updates on putative bull shark (Carcharhinus leucas) occurrences in the upper Mississippi River Basin of North America

A previous paper in this journal by Shell and Gardner assessed various factors around the exploration of the Mississippi River by bull sharks (Carcharhinus leucas Müller and Henle, 1839) based on two twentieth-century occurrences. Recent evidence has suggested one of these occurrences is a probable hoax. Here, we provide a correction to our earlier paper, as well as additional comments on extralimital euryhaline vertebrates in the Mississippi River system, the environmental and historical contexts for their exploration into riverine systems, and suggest steps for any future effort to detect the usage of these river systems by bull sharks.