Does urbanization influences wing symmetry and size of Enallagma coecum (Odonata: Coenagrionidae) in Puerto Rico?
Urbanization alters stream conditions, creating stress environment for aquatic fauna. Here, we studied how urbanization affects Enallagma coecum, an abundant damselfly in Puerto Rico. We focused on how different levels of urbanization influence the symmetry of male E. coecum and its body size. Nine streams draining the Rio Piedras watershed were selected along a gradient of impermeable surfaces. Twelve to 15 adult males were collected at each stream for a total of 126 specimens. Individuals were preserved and photographed (full body and each wing) for subsequent analysis with the ImageJ program. Chi-square tests were used to evaluate significant differences in wing symmetry variables (interior cells, postnodal fourth row cells and postnodal to stigma veins quantity) between sampling sites. Pearson's correlation tests were made to relate wing symmetry variables and body size with percent impermeable surface area in the watershed. We found a significant correlation (R=-0.70; p<0.05) between interior wing cell symmetry and the amount of impermeable area. Our study indicates that urbanization creates stress conditions that are reflected in individual symmetry. Overall, symmetry appears to be a good indicator of urban impacts on aquatic insect populations.
Limarie Reyes ( Co-Presenter/Co-Author), University of Puerto Rico Rio Piedras, firstname.lastname@example.org;
Alonso Ramirez ( Co-Presenter/Co-Author), University of Puerto Rico Rio Piedras, email@example.com;
Yazminne Meléndez (Primary Presenter/Author), University of Puerto Rico, firstname.lastname@example.org;