White River spinedace (Lepidomeda albivallis) and White River desert suckers (Catostomus clarki) - KFFS

White River spindace (Lepidomeda albivallis) is one of six species in the Lepidomeda genus. One Lepidomeda sp. is extinct and the other five are listed as threatened or endangered under the U.S. endangered species act.

In 1991, 37 White River spinedace counted in the upper northern section of Flag Spring were thought to comprise the entire remaining individuals of this species.  These 37 fish, protected from invasion by predatory largemouth bass (Micropterus salmoides) by a 2 m tall concrete dam, were all large and presumed to be adults nearing their maximum life span. After the eradication of largemouth bass from the Flag Springs complex, spinedace were moved to flowing water down stream of the dam where they had access to warm water in the southern two forks of the Flag Springs complex. White River spinedace were able to successfully reproduce in this new habitat and juvenile White River spinedace have been observed in the southern forks of the Flag Springs complex.

Adult White River spinedace tend to orient toward the bottom of swift sections of stream. Whereas the larvae tend to be found near the surface of slower moving sections. The variation in water velocity by life stage indicates that complex habitats consisting of calm pools interspersed among swiftly flowing riffles may be important for Lepidomedia sp. Temperature, flow, or both may be important characteristics of spawning habitat for Lepidomeda sp. If this temperature is the critical range for White River spinedace reproduction, it would be at the upper end of the historic temperature range for the species,  and warmer than spawning habitat used by a similar Lepidomeda sp. Determining what habitat factors are most important for spinedace reproduction is critical to planning spinedace recovery.

Understanding how native springs fishes that co-occur with White River spinedace partition resources may help to determine critical components of habitat complexity needed to restore the entire ecosystem. Co-occurring species of interest include White River desert sucker (Catostomus clarki), and White River speckled dace (Rhinichthys osculus).

In collaboration with the Nevada Department of Wildlife and the U.S. Fish and Wildlife Service, the Klamath Falls Field Station is studying movement of White River spinedace and White River desert suckers in the Flag Springs Complex. USGS installed passive integrated transponder technology to detect and monitor fish movement throughout the springs. Fish movements will be studied to determine the timing of spawning movements and importance of cool water refugia.

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