Lost River Sucker

Shortnose Sucker

      The Klamath River Basin in southern Oregon is home to four species of suckers, the shortnose sucker (Chasmistes brevirostris), the Lost River sucker (Deltistes luxatus), the Klamath Largescale sucker (Catostomus snyderi) and the Klamath smallscale sucker (Catostomus rimiculus).  The shortnose and Lost River suckers were once among the most abundant lake-dwelling fish in this system.  Large-scale degradation of the Klamath River ecosystem, though, caused these species to decline rapidly in the 1960’s.   The shortnose and Lost River suckers received little attention until they listed as federally endangered in 1988.  Public resources are now being used to understand the biology of these endangered species and their habitats in order to manage them for recovery.  Unfortunately, individuals of several of the populations cannot absolutely be identified based on morphology.  It is critical that we devise a method for absolutely identifying the four sucker taxa within the Klamath River Basin so that biological information coming in from other studies is correctly interpreted for the recovery of the two endangered species.
      Previous genetic and morphological evidence suggests that recent or historical introgressive hybridization may have taken place within the four taxa (Miller and Smith 1981; Harris 1991; Harris and Markle 1993).  These studies, though, have not been conclusive at resolving the reproductive isolation, classification, and systematic relationships of these four taxa.  The overall goal of this project is to characterize the reproductively isolated populations of suckers within the Klamath River Basin and to quantify their relationships to each other based on molecular genetic markers.  The availability of these diagnostic markers will permit field personnel to derive population specific morphological markers at various life history stages for field identification.

      Harris, P.M. 1991. Final Report: Biochemistry and morphology of Upper Klamath  Lake suckers.  Submitted to Oregon Dept. of Fish and Wildlife.
      Harris, P.M., and D.F. Markle. 1993. Draft Report: Mitochondrial DNA screening of Upper Klamath Lake suckers. Submitted to Oregon Dept. of Fish and Wildlife.
      Miller R.R., and G.R. Smith. 1981. Distribution and evolution of Chasmistes (Pisces:Catostomidae) in western North America. Occ. Pap. Mus. Zool., Univ. Mich. No. 696: 1-46p.