The Largetooth Sawfish (scientific name Pristis pristis language name Tyemirerriny) can be found in the freshwater section of big rivers in north Australia and so some people also call it the Freshwater Sawfish. It used to be found in many regions across the world, but these days they have disappeared from many of these, and north Australia is now one of the last places where there are still good numbers anywhere in the world. The population has gone down so much that they are said to be ‘Critically Endangered’ on a global scale, meaning scientists think they could go extinct in the near future. Because of this, they have been given special legal protection in Australia.
This sawfish has a very interesting lifecycle, and can be found in different places at different ages. The mothers give birth to babies (called pups) in an estuary. The pups then swim upstream to the freshwater section of rivers, where they live for several years (up to 4–5 years). Once they are older they swim downstream and back out to the ocean where they live as adults. When they are old enough to breed the females come back to the same estuary where they were born to have their own babies.
While they are living in the freshwater they sometimes follow flood waters out of the main river channels and into waterholes. As water levels recede in the dry season, they are forced into remaining isolated waterholes, where they become stuck until the next wet season. This is a natural process, and it normal that some of them might die if they waterhole they are in dries up before the next wet season arrives. But there are two problems these days: 1) There aren’t many sawfish left to keep the population going; and 2) the weather is changing so they are drying out more often and the waterholes that do still hold water are not as safe anymore, and feral buffalo and pigs are making the water unhealthy.