The Grass Valley speckled dace ('' Rhinichthys osculus reliquus'') occurred in a single spring-fed creek in a grassy meadow in eastern

Lander County Lander County is a county in the U.S. state of Nevada. As of the 2020 census, the population was 5,734. Its county seat is Battle Mountain. History Lander County was created in 1862 as the result of a mining boom on the Reese River along the ...

, Nevada. Specimens were collected only once in 1938, and it was then considered common. The species had a distinctive speckled lower lip and silver sided body. The introduction of

brook A brook is a small river or natural stream of fresh water. It may also refer to: Computing *Brook, a programming language for GPU programming based on C *Brook+, an explicit data-parallel C compiler * BrookGPU, a framework for GPGPU programm ...

and

rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coasta ...

to the creek is believed to be the reason for their extinction.

References

Rhinichthys Fish of North America becoming extinct since 1500 Dace, Grass Valley speckled Natural history of Nevada Extinct animals of the United States Fauna without expected TNC conservation status {{Leuciscinae-stub