The relative abundance of D. polymorpha and other benthic macroinvertebrates in lake Büyük Akgöl was studied in 2009, 2012 and 2014. In 2009, the macroinvertebrate fauna consisted of Gastropoda (53.4%), Bivalvia (26.8%), Oligochaeta (12.6%), Chironomidae (5.9%) and other taxonomic groups (Trichoptera, Ceratopogonidae, Ephemeroptera, Odonata, Chaoboridae, and Hirudinea) (1.04%). After three years, Bivalvia and Oligochaeta increased (38.2% and 15.3%, respectively), whereas the other groups (in particular, Gastropoda and Chironomidae) were found to decrease (41.4% and 4.5%, respectively). For the study period, the relative abundance of D. polymorpha increased from 19.6% (2009) to 34.8% (2014). The species has occupied various benthic habitats of lake Büyük Akgöl and continued to spread during the study period.
