New Zealand grayling


The New Zealand grayling, also known as upokororo, pokororo, paneroro, and kanaekura, is an extinct smelt of the genus Prototroctes, which was found only in lowland rivers and streams of New Zealand. They were an amphidromous species—spawning in freshwater streams and developing to maturity in saltwater. Their length was between 20 and 40 cm.
Though abundant through the early colonial period, by the 1870s their population had declined. The last known specimen was caught in the late 1920s to early 1930s. Deforestation and predation, competition and disease from introduced trout likely led to the New Zealand grayling's extinction. The impact of introduced diseases from trout has a parallel in Australia, where utterly immense fish kills of the closely related Australian grayling were caused by introduced strains of Saprolegnia shortly after widespread trout stocking commenced. Tasmanian populations of Australian have never recovered from this blow and remain relatively vestigial.
In 1951, some years after the last sighting, the species was given full legal protection by the Freshwater Fisheries Regulations, the only New Zealand native freshwater fish to be protected.
In August 2018 the New Zealand Department of Conservation classified the New Zealand grayling as "Extinct" under the New Zealand Threat Classification System.