EFFECTS OF DIDYMOSPHENIA ON LARVAL CHIRONOMID DIVERISITY AND FEEDING STRUCTURES
Didymosphenia geminata (didymo) blooms alter the biotic diversity and distribution of freshwater invertebrates, including the reduction of many mayfly, stonefly and caddisfly taxa and their abundances. However, some macroinvertebrate taxa, including oligochaete worms and non-biting midges (chironomids), are tolerant to didymo and increase in abundance. Interestingly, mainly chironomids of the sub-family Orthocladiinae seem to experience this increase in abundance, possibly aided by their consumption of didymo. These dietary changes can potentially impact larval feeding structures, including the mentum. This study examined 1) the differences in genus level diversity of larval chironomids in streams impacted by didymo, 2) the contributions of didymo frustules (siliceous tests) to their diet, and 3) the impact of dietary changes to the wear of menta. Our preliminary results suggest that only a few taxa comprise the majority of chironomids in impacted streams, and those genera consume didymo frustules. Further, menta wearing was most prevalent in chironomid taxa with didymo frustules in their gut contents. Our results suggest that some didymo tolerant chironomids consume didymo frustules, facilitating the increase in chironomid populations, unlike other insect taxa, despite increased wearing on their feeding structures.
Peter Blum (Primary Presenter/Author), Tennessee Technological University, firstname.lastname@example.org;
Matthew Green (Co-Presenter/Co-Author), Clemson University , email@example.com;
Shea Tuberty (Co-Presenter/Co-Author), Appalachian State University, firstname.lastname@example.org ;
Justin Murdock (Co-Presenter/Co-Author), Tennessee Tech University, email@example.com;