Date of Award
Open Access Thesis
Master of Science (MS)
Sherry L. Harrel
David M. Hayes
Stephen C. Richter
The banded pygmy sunfish Elassoma zonatum is a wide-ranging species found throughout the Southeastern Coastal Plain of North America. In Kentucky, the populations are found above and below the inner boundary of the Coastal Plain. Due to their geographical separation comparisons in body size and morphological features along with genetic comparisons using mitochondrial cytochrome-b (Cyt-b) were conducted to test relationships between populations. Two sites, Cypress Creek in the Lower Green River system and Rose Creek in the Tradewater River drainage, were sampled from above the inner boundary and two additional sites, Bayou de Chien and Running Slough in the Mississippi River drainage, were sampled from below the boundary line. Collections from Rose Creek and Running Slough yielded no adult specimens for body measurement/morphological comparisons and were only used for genetic comparisons.
Using principal components analysis (PCA) of body measurements, minimal separation in body sizes was detected between drainages when males and females were combined (PC1 48.9%, PC2 16.7%). When separating sexes, complete separation was observed between both sites, PC1 62% and PC2 12.55% for females and PC1 48.19% and PC2 15.02% in males. PCA comparisons were also conducted using 12 morphological landmarks in geometric morphological analysis but yielded no distinct separation in drainages.
Cyt-b comparisons were conducted using sampled individuals in addition to 25 NCBI sequences of Elassoma zonatum collected from nearby drainages. Phylogenetic trees were constructed using maximum likelihood analysis and indicated that individuals from Rose Creek and Cypress Creek were nearly identical to each other and with individuals from another population collected above the fall line in Running Lake, Illinois and had low genetic diversity while sampled individuals from Bayou de Chien and Running Slough had greater genetic diversity. Haplotype networks were constructed that indicated populations found above the Coastal Plain region were very similar to each other and could be indicative of a northward range expansion after the Wisconsin Glacial Episode.
Copyright 2017 David Cravens
Cravens, David, "Comparison of Cytochrome b variation and morphological features of isolated Banded Pygmy Sunfish (Elassoma zonatum) populations in the lower Green River and Coastal Plain systems in Western Kentucky" (2017). Online Theses and Dissertations. 517.