Degree Name

Master of Science (MS)

Semester of Degree Completion

2002

Thesis Director

Robert U. "Bud" Fischer

Abstract

Dollar sunfish (Lepomis marginatus) at the Savannah River Site were sampled from two radiocesium contaminated ponds with a history of thermal elevation and from reference ponds with no history of radioactive or thermal contamination. Fluorescent sequencing of a portion of the mitochondrial control region showed no genetic variation within or between populations. Centrarchidae microsatellite loci Lma 120 (6 alleles, N=124 from 5 populations), Lma 20 (10 alleles, N=37 from 3 populations) and Rb 7 (14 alleles. N=17 from 2 populations) were variable for dollar sunfish. An additional 9 microsatellite primer pairs were designed for dollar sunfish. Testing of the designed primers on ≥20 individuals from 5 populations showed these loci have a high number of alleles ranging from 4 to 14 (mean = 8.6) and observed heterozygosities ranged from 0.500 to 0.857 (mean heterozygosity = 0.6337). Age analysis showed most individuals were 1-3 years of age. Only 14 individuals from two contaminated sites, Pond C and the West Arm of PAR, had levels of radiocesium in their muscle tissue above the detection limit. Tissue samples need to be re-measured using larger quantities of tissue for more accurate results in order to correlate radiocesium concentration to fish age. Overall, no comparison of genetic variation could be made for contaminated and uncontaminated ponds using mitochondrial DNA. However, new microsatellite primers for dollar sunfish have been designed for future analyses, and preliminary results indicate that they will be adequate for examining genetic variation for this species.

Download

Share

COinS