Received: 1993 Mar 15; Revised: 1993 May 03
The reported range of the spotted sucker (Minytrema melanops) extends roughly through the eastern half of Oklahoma (1). The only collections from a more western longitude were from the Colorado River drainage in Texas (2).
In 1991, we captured and released a single adult specimen during an electrofishing survey of Lake Lawtonka in Comanche County of southwest Oklahoma. Subsequent review of Oklahoma Department of Wildlife Conservation (ODWC) records revealed that spotted suckers have been taken sporadically from Lake Lawtonka since at least 1952.
Spotted suckers were collected from Lake Lawtonka in a ten-hectare rotenone survey by the ODWC in 1952 (unpublished data-no sizes given). Spotted suckers were also killed in a lake-wide fish eradication effort in 1953 (3). In 1973, a single immature spotted sucker (total length = 203 mm, weight = 104 g) was collected in a cove-rotenone survey of lake Lawtonka (4), and one adult (356 mm, 482 g) was collected by rotenone use in 1977 (unpublished ODWC data). In 1982, one specimen (length unknown, 292 g) was recorded from gill-net sampling in the lake (5).
In the spring of 1992, we collected a young spotted sucker (200 mm) and three adults (297, 344, and 362 mm) by electrofishing in Lake Lawtonka. In April and May of 1992, an angler caught eight spotted suckers below Lake Lawtonka in Medicine Creek (S19, T3N, R12W) using live worms. Two of these fish (295 and 395 mm), and the four captured from Lake Lawtonka in 1992 were deposited at the University of Oklahoma Museum of Zoology.
Several spotted suckers were seen and photographed during a snorkel survey of the headwaters of Lake Lawtonka in August, 1992, specifically in lower Jimmy Creek near its confluence with Medicine Creek (near Meers, Oklahoma; S33, T4N, R13W). Riffle areas of the stream were interrupted by pools averaging 10 × 2 × 1.5 m (l × w × d). The water was clear, with a small flow of spring effluent over sand and bedrock substrate.
This stream habitat in the Wichita Mountains is atypical of western Oklahoma, but is consistent with that reportedly preferred by the spotted sucker in other regions (1). Miller and Robison also stated that spotted suckers do well in some eastern Oklahoma lakes. Lake Lawtonka is more similar to those reservoirs in habitat than to other western lakes.
These collections demonstrate a small but viable population of the spotted sucker in Lake Lawtonka and Medicine Creek above and below the lake. Introduction of the population to the region is possible, since fish stockings into these waters from eastern hatcheries began shortly after 1900. However, several other insular fish populations (e.g. Phoxinus erythrogaster, Moxostoma erythrurum, Labidesthes sicculus, Micropterus punctulatus) inhabit the streams of the Wichita Mountains (1). The habitat and faunal diversity of the area suggest instead that spotted suckers are an endemic species, overlooked in historical field surveys of the Wichita Mountains.
1. Miller, R.J., and Robison, H.W., The Fishes of Oklahoma, Oklahoma State University Press, Stillwater, OK (1973).
2. Lee, D.S., Gilbert, C.R., Hocutt, C.H., Jenkins, R.E., McAllister, D.E., and Stauffer, J.R. (Eds.) Atlas of North American Freshwater Fishes, North Carolina Biological Survey, N.C. State Museum of Natural Sciences Publication 1980-12, Raleigh, NC (1980).
3. Wilson, C. Jr., and McCoy, H.A., Lake Lawtonka Fisheries Management Report, 1953. Oklahoma Department of Wildlife Conservation Report 4-53, Oklahoma City, OK (1953).
4. Cook, K. D., Lake Lawtonka Summary
Report, Oklahoma Department of Wildlife Conservation Federal Aid Report, F-15-R-12, Job 2, Oklahoma City, OK (1976).
5. Wyatt, T., and Cook, K.D., Fish Management Surveys and Recommendations for Lake Lawtonka. Oklahoma Department of Wildlife Conservation Federal Aid Report, F-38-R-5, Oklahoma City, OK (1982).