Alterations of Lake Michigan Benthic Communities by the Invasive Colonial Hydroid, Cordylophora caspia: Effects on Fish Prey

March 1, 2006 to February 29, 2008CompletedProject

The objective of this project is to determine the impact of the invasive, Ponto-Caspian colonial hydroid, Cordylophora caspia on benthic invertebrate communities in southern Lake Michigan. We propose to address two fundamental questions related to the presence of Cordylophora in southern Lake Michigan: 1) What is the predatory role of this hydroid in Lake Michigan macrobenthic communities?, and 2) Does the filamentous structure of this hydroid enhance macroinvertebrate abundances in zebra mussel colonies? More specifically, we will determine how this benthic invertebrate influences prey availability for fish. We propose a project examining three objectives involving field and laboratory research to assess the effects of Cordylophora on benthic invertebrates in southwestern Lake Michigan: 1) document specific locations and diets of Cordylophora (specifically at sites where it is associated with zebra mussel colonies); 2) characterize feeding preferences of Cordylophora on common Lake Michigan benthic invertebrates using laboratory feeding experiments; 3) compare species composition and abundances of invertebrates present in mussel colonies with and without Cordylophora to assess the impact of this hydroid as a predator that decreases fish food availability and/or as a filamentous substratum that enhances invertebrate densities in freshwater benthic invertebrate communities. (Lake Michigan); (AIS); (aquatic invasive species); (aquatic invasive plant); (aquatic invasive plants); (zebra mussel); (zebra mussels); (Ponto-Caspian); (hydroid); (hydroids); (Cordylophora caspia); (Cordylophora); (Dreissena polymorpha); (dreissenids); (dreissenid); (benthos); (benthic); (invertebrates); (invertebrate); (exotic species)

Project Data
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Associated Researchers
Attached Publications
  • Folino-Rorem, NC, Sauer, Joe and Klassen, Lindsey (2007) The Effects of Salinity on the Growth and Morphology of the Colonial Hydroid Cordylophora spp. IN PREP: Journal of Experimental Zoology.

  • Folino-Rorem, NC and James Stoeckel (2006) Exploring the coexistence of the hydroid Cordylophora caspia and the zebra mussel Dreissena polymorpha: counterbalancing effects of filamentous substrate and predation. Aquatic Invaders 17 (2): 8-16

  • Folino-Rorem, Nadine, James Stoeckel, Emily Thorn and Laura Page (2006) Effects of artificial filamentous substrate on zebra mussel (Dreissena polymorpha) settlement. Biological Invasions 8:89-96

  • Nadine C. Folino-Rorem, D'Ausilio, Cori Ann, Nancy Schable, John A. Darling. (2007). Genetic analysis reveals multiple cryptic species for the invasive, euryhaline hydrozoan genus Cordylophora. IN PREP Biological Invasions.