Ja. Stoeckel et al., ESTABLISHMENT OF DAPHNIA-LUMHOLTZI (AN EXOTIC ZOOPLANKTER) IN THE ILLINOIS RIVER, Journal of freshwater ecology, 11(3), 1996, pp. 377-379
Daphnia lumholtzi, an exotic zooplankter, recently has become establis
hed in the Illinois River. This species was first detected at Illinois
River Mile (IRM)121.1 near Havana, Illinois in June of 1995, and exhi
bited a peak abundance of 22.5/L in August. Population trends and dens
ities in the Illinois River resemble those reported in lakes and reser
voirs of the southeastern United States, suggesting D. lumholtzi is ad
aptable to lotic as well as lentic systems. Individuals were found at
sampling sites as far upriver as IRM 195.9.