The New Guinea River shark or Northern River shark (Glyphis garricki), is an extremely rare and critically endangered large species of river shark that may reach up to 8.2 feet and possibly up to 10 feet in length that inhabits remote tidal rivers of Australia’s Northern territory, northern Queensland, and Papua New Guinea. The New Guinea River shark has adaptive senses, smaller eyes with poor vision, and a greater concentration of ampullae of Lorenzini to support its living conditions in dark, murky river and brackish waters.
Family: Carcharhinidae – Requiem sharks
Genus: glyphis
Species: garricki
Phylum– Chordata
Class– Chondrichthyles
Subclass– Elasmobranchii
Common Name– Ground Sharks
Common Name– Requiem Sharks
Genus– Glyphis
Species– garricki
Status: IUCN Red List CRITICALLY ENDANGERED
Average Size and Length: The Northern or New Guinea River shark is born under 70 cm and are thought to grow to 200 cm or longer at adulthood.
Teeth and Jaw: The upper teeth are high and broad with serrated triangular cusps. The first few lower front teeth are long and hooked with protruding cusps. They have serrated cutting edges that move into spear-like tips. There are no cusplets.
Head: The New Guinea River shark has a flat head with a broadly rounded snout. The eyes are tiny.
Demographic, Distribution, Habitat, Environment and Range: The New Guinea River or Northern River shark can be found in Papua New Guinea and Northern Australia. It prefers turbid, brackish freshwater in rivers and the closest marine waters. They seem to frequent low-salinity waters that are murky with low visibility.
Diet: Presumed piscivorous and preferring very small bony fishes.
Aesthetic Identification: The New Guinea River shark or Northern River shark is slender and large. It is grey with no other body markings. The fin margins are dusky in color. It is counter-shaded white underneath. There is no interdorsal ridge. There is a longitudinal upper precaudal pit. The first dorsal fin originates over the rear thirds of the pectoral bases. The second dorsal fin originates about two-thirds the height of the first dorsal fin. The anal fin has a deeply notched posterior margin.
Biology and Reproduction: Scientists believe possibly viviparous.
Behavioral Traits, Sensing and Intelligence: The Northern River shark has very small eyes, and thus very poor vision. To make up for its poor vision, the New Guinea River shark has a higher than normal concentration of ampullae of Lorenzini.
New Guinea River Shark Future and Conservation: Very rare and critically endangered, it can easily fall victim to fishing and habitat degradation.
New Guinea River Shark Recorded Attacks on Humans: No threat or danger to humans.