The Ganges shark (Glyphis gangeticus) is a critically endangered species of requiem shark found in the Ganges River and the Brahmaputra River of India. It is often confused with the more common bull shark (Carcharhinus leucas), which also inhabits the Ganges River and is sometimes incorrectly referred to as the Ganges shark. Unlike bull sharks, which need to migrate to salt water to reproduce, species in the genus Glyphis are true river sharks. The genus contains a total of six known species, only half of which are described. In contrast, genetic evidence has shown that both the Borneo river shark (G. fowlerae) and Irrawaddy river shark (G. siamensis) should be regarded as synonyms of the Ganges shark, expanding the range of the species to Pakistan, Myanmar, Borneo and Java. Even with this expanded range, the species remains very poorly known and very rare.