The New Zealand grayling, Prototroctes oxyrhynchus, 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 1860s their population began to decline. The last known specimen was caught in the late 1920s to early 1930s. Deforestation and competition from feral trout may have contributed to the New Zealand grayling's extinction.