|Rooney, Alejandro - Alex|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2003
Publication Date: N/A
Technical Abstract: We investigated population differentiation and haplotype diversity among seasonally fragmented populations of three stream fishes in the Ouachita Mountains, Arkansas. Within intermittent streams, riffles may dry during the summer, resulting in nearly to completely isolated pools. We sampled Lepomis megalotis (longear sunfish), Etheostoma whipplei (red fin darter), and Fundulus olivaceus (black-spotted topminnow) from five isolated pools in the Alum Fork of the Saline River (above Lake Winona) and two spring-fed, perennial tributaries in the Saline River system (downstream from Lake Winona) during September 2001 and 2002. We assessed variability of the control region of the mitochondrial DNA on polyacrylamide gels with use of temporal temperature gradient electrophoresis (TTGE). We found temporal population differentiation (between years) for L. megalotis and F. olivaceus. Lepomis megalotis populations also were spatially differentiated along the stream gradient, but populations of F. olivaceus and E. whipplei were not. Haplotype diversity did not differ spatially for any species. After combining data for populations above Lake Winona, we observed significantly higher haplotype diversity below the reservoir for F. olivaceus and E. whipplei. Therefore, stream fragmentation appears be associated with reduced haplotype diversity for some species. Spatiotemporal patterns of population differentiation were most obvious for L. megalotis, but less evident for F. olivaceus and E. whipplei which are putatively better dispersers than L. megalotis. Thus, stream fragmentation influences gene flow which appears to be correlated with species-specific dispersal capability.