River sharks are thought to be particularly vulnerable to habitat changes.

Like other members of its genus, the northern river shark has a stocky body with a high back.

The river sharks are members of the family Carcharhinidae, and thus share the basic characteristics of the group.

It is similar to other river sharks in having a stocky grey body with a high back, tiny eyes, and broad fins.

The Bizant river shark is a rare species of fresh or brackish water shark.

However, their life history cycle is probably similar to other river sharks, characterized by long gestation, slow growth, delayed maturity, and small litter size.

Northern river sharks are likely piscivorous.

The Northern river shark is known to inhabit the tidal region of the river nd has been found further upstream.

Despite fishing and scientific surveys in the area, no more Irrawaddy river sharks have been recorded in the hundred-plus years since the first.

In Africa, it is also commonly called the Zambezi River shark or just Zambi.

Glyphis garricki (Northern river shark)

Unlike bull sharks, which need to migrate to salt water to reproduce, species in the genus Glyphis are true river sharks.

The river sharks in the Ord River of Western Australia may also be of this species.

Glyphis fowlerae (Borneo river shark)

Glyphis siamensis (Irrawaddy river shark)

The Borneo river shark, Glyphis fowlerae, is a shark of the family Carcharhinidae.

The river sharks are five rare species of shark in the genus Glyphis, although, due to their secretive habits, other species could easily remain undiscovered.

Like other river sharks, its body is robustly built with a high back that slopes down to a broadly rounded snout shorter than the mouth is wide.

Intensive artisanal fishing, mainly gillnetting but also line and electrofishing, occurs in the stretch of river where the sole Irrawaddy river shark specimen was caught.

The northern river shark appears to be extremely rare, though more subpopulations may remain to be discovered in Australia and Papua New Guinea.

However, the use of Glyphis to encompass the river sharks did not gain wide acceptance until Jack Garrick's 1982 revision of Carcharhinus.

Extremely rare like other river sharks, its global population has been estimated to number no more than 2,500 mature individuals, with no more than 250 in any subpopulation.

Bull sharks are not actually true freshwater sharks, despite their ability to survive in freshwater habitats (unlike the river sharks of the genus Glyphis).

But since little is known about the behaviour of genuine freshwater river sharks, and since G. gangeticus is critically endangered, contact with humans is probably very rare.

Northern River Shark, New Guinea river shark Glyphis sp.

Glyphis species, like other sharks, exhibit a very slow rate of genetic change.

It is worth noting that the size at birth or maturity is unknown for any other Glyphis species.

Glyphis: from Greek glyphe, meaning 'carving'

The river sharks are five rare species of shark in the genus Glyphis, although, due to their secretive habits, other species could easily remain undiscovered.

However, the use of Glyphis to encompass the river sharks did not gain wide acceptance until Jack Garrick's 1982 revision of Carcharhinus.

The bull shark is sometimes called both the river shark and the Ganges shark; it should not be confused with the true river sharks of 'Glyphis'.

Among these the most distinguished are species within the Graphis, Arthonia, Glyphis, Opegrapha, Chrysothrix, Cryptothecia, and Trypethelium genera.

German biologists Johannes Müller and Jakob Henle originally described the speartooth shark as Carcharias (Prionodon) glyphis, in their 1839-41 Systematische Beschreibung der Plagiostomen.