Exotic Freshwater Molluscs in Illinois Jeremy S. Tiemann, Kevin S. Cummings, Sarah A. Douglass & Mark A. Davis Illinois Natural History Survey Champaign, Illinois 61820 jtiemann@illinois.edu
Class Bivalvia Freshwater Mussels and Clams Family Corbiculidae Corbicula fluminea (Müller, 1774) Asian Clam Family Dreissenidae Dreissena polymorpha (Pallas, 1771) Zebra Mussel Dreissena bugensis (Andrusov, 1897) Quagga Mussel Family Sphaeriidae Eupera cubensis (Prime, 1865) Mottled Fingernail Clam
Class Gastropoda Freshwater Snails Prosobranchs Family Vivparidae Bellamya chinensis (Reeve, 1863) Chinese Mysterysnail Bellamya japonica (von Martens, 1861) Japanese Mysterysnail Family Bithyniidae Bithynia tentaculata (Linnaeus, 1758) Mud Bithynia Family Valvatidae Valvata piscinalis (Müller, 1774) European Stream Valvata Family Hydrobiidae Potamopyrgus antipodarum (Gray, 1853) New Zealand Mudsnail Pulmonates Family Lymnaeidae Radix auricularia (Linnaeus, 1758) Big-ear Radix
Genus Corbicula Corbicula has been described as a hyper-invasive alien with great biofouling capabilities. >$1,000,000,000 damages to power plants & water systems. Also alter benthic substrates & compete with native species. Corbicula in Lake Tahoe Corbicula in Salt Fork, Vermilion County, Illinoi
Genus Corbicula Corbicula taxonomy is muddled and unclear, as is the number of species established in North America. Genetics is a mess because of unique hermaphroditic, clonal lineages that lack meiosis, generate unreduced biflagellate sperm, and come in diploid, triploid or tetraploid genomic iterations that can be androgentic. Meiosis Chromosomes = 2N or 3N or 4N Literature reports vary from an invasion of only a single species to invasions of multiple species.
Corbicula fluminea (Müller, 1774) Corbicula fluminea first recorded in North America in 1924 in British Columbia. Since has spread throughout the U.S. & Mexico. The Midwest long recognized as having only C. fluminea.
Corbicula fluminea (Müller, 1774) Corbicula fluminea first recorded in North America in 1924 in British Columbia. Since has spread throughout the U.S. & Mexico. The Midwest long recognized as having only C. fluminea.
Corbicula cf. largillierti (Philippi, 1844) Corbicula cf. largillierti might have invaded from southern U.S. First occurrence in Illinois in 2008 in the Ohio River Also found in Miss. & Illinois rivers C. fluminea Differences = purple nacre & tight, compressed ridges C. cf. largillierti
Mystery Corbiculid Corbicula??? found in Illinois River, Marseilles, Oct. 2015 C. fluminea Differences = creamy nacre, purple laterals, rust-colored rays, & ridges not as pronounced C. cf. largillierti?????
Are we crazy? All three species occur syntopically in the Illinois River. >250 indiv. of each collected. Combined genomic & morphometric assessment will be used to verify that this discovery is a novel invasion. UMMZ will conduct the next generation genomics. INHS will run the geometric morphometric assessment.
Discussion Accurate species delimitations are essential in developing predictive invasion / dispersal models and assessing potential effects on aquatic ecosystems. Given the rate of C. fluminea colonization, new Corbicula invaders could quickly attain continental distribution. Cumulative Corbicula biomasses could interfere with native mussels, including negative effects on restoration efforts of threatened and endangered species. Please alert us to the presence of unusual Corbiculids in your study areas if encountered