Marti Sanders


Dr. James Kennedy
Research Topic: 
Anthropogenic Activities Effect on the Growth and Development of Representative Dragonflies (Odonata: Libellulidae) from Denton, TX Watersheds
Urbanization can have detrimental impacts to ecological environments in and around urbanized areas. One way to measure the level and severity of the impacts urbanization has on aquatic ecosystems is through biological monitoring. The Benthic Ecology Laboratory at UNT is currently conducting a large-scale study to determine how urbanization and watershed characteristics affect the population and diversity of benthic macroinvertebrates from six watersheds in Denton, TX. This segment of the study focuses on the growth and development of representative dragonflies from these watersheds. The results from this study will be integrated with ongoing projects to provide a conservation strategy to help protect Denton’s freshwater resources. Dragonfly nymphs were collected in May 2017 from six watersheds in Denton using sweep nets inside a one-meter squared area from three different habitats. The nymph’s hind wing, thorax, and head width were measured using an OMAX digital microscope camera and Troup View software. The measurements indicated that the ponds with the least anthropogenic influences had a diverse range in development stages of dragonfly naiads present compared to those with the most impacts. This implies that better water quality supports increased reproduction and development of benthic macroinvertebrates and ultimately healthier ecosystems. During the process of collecting the growth and development data, it was noted that over one-third of the nymphs from these ponds contained unknown white particles throughout their body. Analytical testing to determine the chemical composition of these particles is ongoing, as well as their effects on the nymph’s development.