Endangered cui-ui of Pyramid Lake, Nevada

By:  and 
Edited by: Edward T. LaRoeGaye S. FarrisCatherine E. PuckettPeter D. Doran, and Michael J. Mac



Cui-ui (Chasmistes cujus) is a large plankton-feeding fish that only occurs in Pyramid Lake, Nevada. It was put on the federal endangered list in 1967 based on declining population and absence of reproduction. A lake dweller, cui-ui is a stream spawner. Most of this century, this sucker species was unable to access the Truckee River, Pyramid Lake's only perennial tributary, to reproduce. Water diversion from the Truckee River, as a result of the nation's first Bureau of Reclamation project (Newlands Project), reduced the lake elevation and, in most years, caused an impassable delta to form at the mouth of the Truckee River. Cui-ui live more than 40 years; it is this longevity that has allowed the species to persist for as many as 19 years with virtually no recruitment (see glossary) to the adult population (Scoppettone 1988).

Cui-ui is one of three remaining species of the genus Chasmistes. Of the three, its habitat is most intact, and it thus has the best opportunity for recovery (Scoppettone and Vinyard 1991). Each spring, cui-ui adults, most of which mature at 8-12 years of age, migrate to the mouth of the Truckee River at the south end of Pyramid Lake, where they aggregate, awaiting environmental cues and sufficient stream flow to enter the river (Scoppettone et al. 1986). This behavior provides an excellent opportunity to capture the adults for estimating population numbers and year-class (year hatched) structure. In this article we report changes in adult cui-ui population number and year-class structure from spring 1983 to spring 1993.

Publication type Book chapter
Publication Subtype Book Chapter
Title Endangered cui-ui of Pyramid Lake, Nevada
Year Published 1995
Language English
Publisher National Biological Service
Publisher location Washington, D.C
Contributing office(s) Western Fisheries Research Center
Description 2 p.
Larger Work Type Book
Larger Work Subtype Monograph
Larger Work Title Our living resources: A report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems
First page 323
Last page 324
Country United States
State Nevada
Other Geospatial Pyramid Lake
Google Analytic Metrics Metrics page
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