Moore High School, Moore, Oklahoma, and State Environmental Laboratory, Oklahoma State Department of Health, Oklahoma City, Oklahoma.
The Red River pupfish is common in the sandy-bottomed rivers and streams of the Red River drainage in southwestern Oklahoma. R. J. Miller and H. W. Robison (1) have indicated that this species was limited to the Red River drainage in Oklahoma and there is no known record of this fish being collected in the Arkansas River drainage before 1969. The first indication that this species occurs in the South Canadian River drainage was when several small specimens were collected in 1969 by B. B. Moser (personal communication, Oklahoma Department of Wildlife Conservation) from a small tributary of the river 7 miles northwest of Ada, Oklahoma, in Pontotoc County (Section 5, T-5-N, R-4-E). Attempts to find this site and make additional collections have been unsuccessful. The first known collection of this species in the Arkansas River drainage was by F. B. Cross (personal communication) on April 22, 1972, from a small, clear, braided channel of the Canadian River at Texas Highway 70 in Robert County, Texas. The single specimen was catalogued into the Kansas University Museum of Natural History as KU14707.
On May 21, 1981, two specimens of the Red River pupfish were collected by the Biotrend Survey Team from the Oklahoma State Department of Health (OSDH) from a backwater channel of the South Canadian River south of Wanette (Section 12, T-5-N, R-2-E) in Pottawatomie County. This is the first known record of this species from the Arkansas River drainage in Oklahoma. These specimens were catalogued as number 826 into the OSDH fish collections in Oklahoma City. During the fall sampling on September, 1982, a second collection of this species was made at a site on the South Canadian River just west of Bridgeport in Blaine County (Section 33, T-13-N, R-11-W) by the OSDH Biotrend Survey Team. A single specimen was taken at this site. This was the only time that this species has been collected at this site in 18 trips since 1976.
Two additional collections of the pupfish, in which much larger numbers were found, were made during the summer of 1983 by two of us (Harrison and Gibbs, of Moore High School). On August 16, 1983, fifty-eight specimens were collected from a site five miles north of Roll in Ellis County (Section 10, T-16-N, R-22-W) on State Highway 283. Later, on August 18, 1983, a second collection of fifty-seven specimens was made at a point on the South Canadian River just south of Camargo in Dewey County (Section 12, T-18-N, R-17-W) on State Highway 183. The river at the site was not flowing and consisted of two or three shallow pools. The large numbers of this species at both sites would indicate a well established population of this species in the western sections of the South Canadian River.
The eastward expansion of this species appears to be limited to west of Calvin in Hughes County (Section 22, T-6-N, R-10-E). Sixteen collections at this site since 1977 have failed to produce pupfish.
1. R. J. MILLER and H. W. ROBISON, Fishes of Oklahoma, Oklahoma State University Press, Stillwater, Oklahoma, 1973.