Are there bull sharks in rivers in Indiana?

There are no bull sharks in the rivers of Indiana; however, bull sharks are one of two shark species with the unique ability to survive in both freshwater and saltwater. Sightings of bull sharks have been reported at 2,200 miles upstream in both the Amazon River and the Mississippi River.

Bull sharks are able to survive entirely in freshwater, because their kidneys can gradually adjust to the salinity of the water. As they migrate from the ocean into estuaries and rivers, their kidneys remove less salt and more urea from the bloodstream through urination, reversing the normal marine shark method of osmoregulation.