SPECIES CODE: E04T V01
Listed Threatened with Critical Habitat on March 31, 1986 (51 FR 10857 10865). Recovery Plan approved on March 15, 1997.
Note: All descriptions are abstracted and/or taken from the Recovery Plan (1996), excluding information cited from the NatureServe Explorer (2001).
REPRODUCTION AND DEVELOPMENT:
of the reproductive organs of
RANGE AND POPULATION LEVEL:
No numerical estimates of the Duckwater Indian Reservation populations have ever been made. The Big Warm Spring population was described as “teeming” and “abundant” during the 1930’s, but declined to “exceedingly rare” between 1981 and 1982, following introduction of nonnative fishes and installation of a catfish rearing facility. A “teeming population occupied Little Warm Spring in 1934, and the springfish remain “common” despite the draining of an associated marsh and diversion of the spring outflow into two ditches.
species has also been introduced into Chimney Springs, approximately six miles
south of Locke’s Ranch, a seepage area which forms small thermal ponds at
springs in which the fish inhabit range from 30ºC to 39ºC, with Chimney Springs
being the hottest, ranging from 63ºC to 66ºC (145ºF to 151ºF). In their natural environment,
of the springs historically inhabited by the
The populations at Chimney Springs have two major setbacks. In 1981, the introduced population at Chimney Springs was lost after spring discharge decreased due to pumping of underground aquifers. Another population was reintroduced after flows resumed. In addition to Chimney Springs, several other springs to the south of Locke’s Ranch
also failed during 1981. In 1988, cattle trampled the berms creating the three ponds, eliminating the fish in the ponds. However, a few were observed downstream and following repair, the fish were able to recolonize the ponds.
In 1984, the outflow channel from Little Warm Spring was channelized and its bordering marsh dried and burned to modify and improve diversions to nearby agricultural lands. Prior to this action, the habitat in Little Warm Spring was the most stable environment occupied by the springfish. Springfish habitat in the channel was approximately 400 yards long, 2 yards wide, and 1 yard deep, lightly vegetated, and bordered by deeply recessed undercut banks supporting mature marsh vegetation. Since channelization, this quality habitat is approximately 20 yards long and 1 yard wide.
Big Warm Spring population has declined due to the introduction of guppies,
mollies (Poecilia sp.), mosquitofish (Gambusia affinis), and
catfish (Ictalurus punctatus).
The introduced fish compete with and prey upon
The long term threat to the
Deacon, J.E., T.B. Hardy, J. Pollard, W. Taylor, J.
Landye, J. Williams, C. Williams, P. Greger, and M. Conrad. 1980. Environmental
analysis of four aquatic habitats in east-central
NatureServe Explorer: An online encyclopedia of
life [web application]. 2001. Version 1.6 .
Williams, C.D. 1986. Life history of the