Abstract:
Six populations of Notropis topeka were sampled from the Arkansas River and Kansas River drainages in the Flint Hills, and one population from Wallace County in extreme western Kansas. Starch-gel electrophoresis was used to examine genic variation of N. topeka at 21 presumptive loci. Mean heterozygosity was greatest in the Arkansas River drainage (H=0.048) and lowest in Wallace County
(H=0.015). Chi-square analysis and F-statistics indicated significant differences among populations in allele frequencies for the six most variable loci. In
addition, averages of Rogers' genetic similarity values for the populations in the Arkansas River drainage were 0.946 and 0.916 for the populations in the Kansas River drainage. There was also a statistically significant correlation between Nei's genetic distance and linear geographic distance between localities. These data indicate that, while gene flow among populations is restricted or stopped, the populations are quite similar and the restriction in gene flow must be recent.
