Endangered Species
Mountain-Prairie Region

KENDALL WARM SPRINGS DACE

Kendall Warm Springs Dace

Species Description:  The Kendall Warm Springs dace (Rhinichthys osculus thermalis) is a member of the Cyprinidae family, and is the only fish species to inhabit the 85° F spring water in the Bridger-Teton National Park in Wyoming.  Adults range from one to two inches in size, with a grayish-green body with dark blotches and a dark lateral stripe on their sides.  Spawning is thought to occur several times a year in shallow pools and streams not more than one foot deep.

Location: The Kendall Warm Springs are located in the Bridger-Teton National Forest in western Wyoming. The spring area and 984 feet of stream comprise the total habitat for the dace.  At an elevation of 7,840 feet, Kendall Warm Springs is made up of numerous thermal seeps and springs scattered along and originating from the north face of a small limestone ridge, the springs flow into a stream which joins the Green River over an embankment.

The Kendall dace are dispersed throughout the stream and use plant growth as their primary escape cover.  Adult dace may occur in small schools within the main channel, but most remain in pools or quiet eddies where plant growth or other debris breaks the current.  For nursery areas Kendall Warm Springs dace fry use still water pockets in the dense mats of aquatic vegetation, as well as backwater areas long the sides of the main channel.

Threats:  Historic threats to the dace include habitat degradation, over-collection, and pollutants.  Stemming from concerns that grazing livestock were adversely affecting the Kendall Warm Springs channel, the Forest Service in 1969 fenced a 160 acre area surrounding the spring to protect it from degradation.  Kendall Warm Springs dace were also historically used as bait fish.  However, in the 1960s, the Wyoming Game and Fish Department prohibited its use for such purpose.  Prior to 1975, the Kendall Warm Springs were also commonly used for bathing and washing clothes.  Rock dams were constructed along the stream to create bathing pools.  Evidence suggests that the use of detergents and soaps in the spring depressed the aquatic community.

Potential threats to the Kendall Warm Springs dace include: 1) water table lowering, disruption of the springs recharge area, or contamination of the area surrounding the Kendall Warm Springs; 2) potential collection of individuals; 3) introduction of exotic fish species into Kendall Warm Springs, and 4) destruction of riparian stream-side vegetation or in-stream habitat.  The management objectives for the recovery of this species are to maintain the existing population and protect its habitat.

Recent Actions:  On December 26, 2012, the Service announced the availability of a draft revised recovery plan for the Kendall Warm Springs dace. The Service solicits review and comment from the public on this draft revised plan through February 25, 2013.

On October 10, 2007, the Service completed the 5-year review for the Kendall Warm Springs dace initiated on September 20, 2006.

More information can be found on the Service's ECOS webpage

Last updated: January 2, 2013