The Northern River Shark, also known as the New Guinea River Shark is one of the rarest species of sharks in the world. Estimates suggest only about 250 adult Northern River Sharks exists, ensuring they will remain on the critically endangered wildlife list
They range from 2.5 to 3 metres and they belong to the family of whaler or requiem sharks
No weight specifications are known to date
Australia, Papua New Guinea
The Northern River Shark has only been reported in a small number of locations in Western Australia, the Northern Territory and Papua New Guinea. They have been reported from King Sound, The Ord River and Doctors Creek near Derby in Western Australia and also in the Adelaide and Alligator Rivers in Australia’s Northern Territory and the Daru region. The Northern River Shark was also spotted in the Fly River in Papua New Guinea.
The Northern River Shark has a steely grey stocky body with a high back and broad fins. The head is wide and flat and they have a long broadly rounded mouth with 31 to 34 upright and triangular teeth with serrated edges in the upper jaw and 30 – 35 narrower, straight and slightly curved teeth rows in the lower jaw. They have very small eyes, but the river shark has a high concentration of ampullae of Lorenzini. These special receptor organs can detect electrical fields of living creatures and they help the shark to locate prey in zero visibility conditions.
The Northern River Shark behaviour consists of:
- This species of river shark is viviparous
- The females bear litters of 9 young every two years before the wet season
- The females give birth to live young that have developed inside her body. The young are born and measures about 67 centimetres
- The males are mature when they reach about 1.2 to 1.4 metres and the female is mature when she reaches lengths of 1.4 to 1.7 metres
- The Northern River Shark hunts fish in water with poor visibility and they move to and from feeding areas with the tide
The Northern River Shark is piscivorous and they prey on small bony fish.
The Northern River Shark inhabits large rivers, estuaries and coastal bays and they prefer turbid, murky water with low visibility or muddy bottoms and large tides. They frequent brackish, low salinity waterways and they venture into fresh water. The juvenile sharks prefer fresh, brackish and salt water and the adult sharks have only been found in marine environments.
The degradation of their natural habitat, limited population numbers and limited distribution place the Northern River Shark under severe threat. There are ongoing threats from damming, mining and water programmes limiting the available habitat needed for the river shark to survive. Commercial fisheries and recreational fishermen catch the Northern river shark legal and illegally with longlines and gillnets
Papua New Guinea unfortunately has no regulations restricting the capture of this species. The federal government in Australia has however developed a multi-species recovery plan. The Northern River Shark is protected at federal and state levels in Western Australia and the Northern territory. Efforts to increase public awareness, education and research have also been undertaken. A better understanding of the biology and ecology of the Northern River Shark is needed to ensure the best strategies are developed to protect the species.