Temporal range: 
|Speartooth shark (Glyphis glyphis) at the Melbourne Aquarium|
|Carcharias (Prionodon) glyphis|
Müller & Henle, 1839
This genus contains only three extant species. Further species could easily remain undiscovered, due to their secretive habits. This genus was thought to contain five different species, but recent studies on molecular data revealed that the species Glyphis gangeticus has an irregular distribution in the Indo-West Pacific region.
The recognized species in this genus are:
- Glyphis gangeticus (J. P. Müller & Henle, 1839) (Ganges shark)
- Glyphis garricki L. J. V. Compagno, W. T. White & Last, 2008 (northern river shark)
- Glyphis glyphis (J. P. Müller & Henle, 1839) (speartooth shark)
- †Glyphis hastalis Agassiz, 1843
- †Glyphis pagoda (Noetling, 1901)
Distribution and habitat
Their precise geographic range is uncertain, but the known species are documented in parts of South Asia, Southeast Asia, New Guinea, and Australia. Of the three currently described species, the Ganges shark is restricted to freshwater, while the northern river shark and the speartooth shark are found in coastal marine waters, as well. While the bull shark (Carcharhinus leucas) is sometimes called both the river shark and the Ganges shark, it should not be confused with the river sharks of the genus Glyphis. Bull sharks evolved to have their offspring in freshwater, therefore, making them safe to roam in the water while other sharks are able to survive in saltwater.
River sharks remain very poorly known to science. They are facing a critically endangered status since they are so poorly studied, and people know very little about their population and life history. One of the primary threats to river sharks is habitat degradation, which includes human development, pollution, and fishing. The river shark is known to be one of the rarest sharks in the world. They have been found in nine different tidal areas, which consist of muddy waters with a low salinity. Their placement in connection to coastal marine waters indicates that they are usually born around October.
Jabado, R. W., et al. “A Rare Contemporary Record of the Critically Endangered Ganges Shark Glyphis Gangeticus.” Journal of Fish Biology, vol. 92, no. 5, Mar. 2018, pp. 1663–1669., doi:10.1111/jfb.13619.
- "Glyphis Agassiz 1843 (river shark)". Fossilworks.
- Li, Chenhong; Corrigan, Shannon; Yang, Lei; Straube, Nicolas; Harris, Mark; Hofreiter, Michael; White, William T; Naylor, Gavin J. P (2015). "DNA capture reveals transoceanic gene flow in endangered river sharks". Proceedings of the National Academy of Sciences. 112 (43): 13302–7. Bibcode:2015PNAS..11213302L. doi:10.1073/pnas.1508735112. PMC 4629339. PMID 26460025.
- Jabado, R. W.; Kyne, P. M.; Nazareth, E.; Sutaria, D. N. (2018). "A rare contemporary record of the Critically Endangered Ganges shark Glyphis gangeticus". Journal of Fish Biology. 92 (5): 1663–1669. doi:10.1111/jfb.13619. ISSN 1095-8649. PMID 29611178.
White WT, Appleyard SA, Sabub B, Kyne PM, Harris M, Lis R, et al. (2015) Rediscovery of the Threatened River Sharks, Glyphis garricki and G. glyphis, in Papua New Guinea. PLoS ONE 10(10): e0140075. https://doi.org/10.1371/journal.pone.0140075