The Status of the Rock Bass Population in Blue Spring, New Mexico, with Comments on the Introduction of Rock Bass in the Western United States

Abstract

The previously undetermined status of the rock bass in Blue Spring, a tributary to the Pecos River drainage in southeastern New Mexico, has created some confusion. One view holds that the population may represent an undescribed form or a native relict that should be protected. Examination of 34 specimens from Blue Spring and detailed comparison with many specimens from eastern popula- tions has led us to conclude that the Blue Spring population represents an introduc- tion of the northern rock bass, Ambloplites rupestris. Information from the New Mexico Department of Game and Fish and records of the U.S. Commission of Fish and Fisheries indicate that Blue Spring rock bass were established from brood stock introduced from east of the Mississippi River between 1891 and 1903. Records for established populations of rock bass in other states west of its native range are briefly mentioned. The status of the rock bass in Blue Spring, a tributary to the Pecos River drainage in southeastern New Mexico, has remained undeter- mined until now. Hubbs and Echelle (1973) reported on the rock bass from Blue Spring. According to these authors there was no evi- dence of introduction and the population appeared to be superficially distinctive. At one time the Blue Spring rock bass was considered for endangered species status. We examined the rock bass material collected by Hubbs and Echelle