Freshwater sharks are a group of shark species that inhabit rivers, lakes, and other freshwater environments. Unlike their ocean-dwelling relatives, these sharks have adapted to live in low-salinity waters. Notable examples include the bull shark, which can travel between saltwater and freshwater, and the Ganges river shark, found in the rivers of India and Bangladesh. These sharks play a crucial role in their ecosystems by helping to maintain the balance of fish populations. Freshwater sharks are generally smaller than their marine counterparts and have unique adaptations, such as the ability to regulate their internal salt levels to survive in freshwater habitats.