Species diversity of mayfly (Ephemeroptera) nymphs in the Lower Ogeechee River Basin

REU Fellow: Thomas Pacious, College of the Holy Cross

Mentors: Dr. Dmitry Apanaskevich, Dr. Checo Colón-Gaud

The Southeastern United States is a hotspot for biodiversity. Mayflies are important indicator group of insects due to their fragility and sensitivity to biotic and abiotic changes in freshwater systems. The Ogeechee River is an unfragmented, sparsely developed river, making it an ideal candidate for mayflies to thrive. Species level sampling has never been documented in the Ogeechee River or the Georgia Coastal Plain. Sampling was conducted to assess the taxonomic diversity of mayfly species that inhabit the Ogeechee River Basin. A total of six species were identified using key morphological characteristics (above). Several species have limited taxonomic resolution due lack of cohesive available descriptive literature. Taxonomic keys proved useful for identifying specimens to the genus level, but species level identification proved difficult due to descriptions being outdated, vague, and including incomparable sets of characters. Better descriptions using the same set of characters (e.g., maxillary palp for the Tricorythodes) could clarify species level differences in this genus. Similar challenges were faced when identifying to species in the genera Callibaetis, Caenis, and Hexagenia. This study identified the need for proper taxonomic revision on the species level for most of the mayfly genera collected.