What it is
The New Zealand grayling (Prototroctes oxyrhynchus) was a slender silvery fish, 30 to 45 centimetres long, that spent part of its life in rivers and part at sea. The International Union for Conservation of Nature lists it as Extinct.
Range
Rivers and streams across New Zealand.
What happened
Māori caught it in great numbers with woven basket traps set in rivers. After European settlement, forest clearing muddied the rivers, fishing increased, and brown and rainbow trout were released from the 1860s.
When / status
Last sighting in 1929.
Human role
Introduced trout, which ate it and took its food, together with fishing and damaged rivers, wiped it out.