Joel Corush
Assistant Professor
Evolutionary Ichthyologist
Biology Department
Illinois Institute of Technology
Robert A. Pritzker Science Center
3105 South Dearborn Street, Room 182
Chicago, IL 60616
email: jcorush@illinoistech.edu
Education
- Postdoc - Illinois Natural History Survey at University of Illinois at Urbana-Champaign
- Postdoc - Wayne State University
- Ph.D. - Ecology and Evolutionary Biology - University of Tennessee - Knoxville
- B.A. - Biology - Drake University
I use population genetics, phylogenetic comparative methods, and natural history to study trait evolution in fishes. My research focuses on how life-history traits—such as breeding behavior and migration patterns—shape population connectivity and movement across landscapes within species, as well as hybridization rates between species. I then compare these behaviors across clades to identify patterns associated with diversification, trait correlations, and the evolution of complex behaviors. I also work to incorporate this information into conservation and management efforts. Two major lines of research in my lab are: (1) the evolution of breeding behavior in North American minnows, and (2) the biogeography and life-history evolution of Indo-Pacific mudskippers.
I am interested in understanding how complex nesting behaviors evolve and the evolutionary consequences of this reproductive strategy. A recent phylogenetic comparative study demonstrated that nest association—using the nests of other species—significantly increases the likelihood of hybridization (Corush et al. 2021). My ongoing research examines the evolutionary pathways that lead to the development of complex breeding behaviors—such as nest building and parental guarding—and quantifies the rates of hybridization associated with specific nest-building strategies among North American minnows.
Mudskippers are a semi-terrestrial group of fishes that spend much of their time on intertidal mudflats. This lifestyle is associated with numerous behavioral, physiological, and morphological adaptations, and may strongly influence biogeographical distribution. My research examines how an amphibious life history can shape dispersal ability, population connectivity, and evolutionary diversification in this clade.
For a full list of publications see my Google Scholar page
Select publications:
- Corush, J. B., Cucalón, R. V., Metzke, B. A., Tan, M., & Davis, M. A. (2025). Pleistocene glaciation and Anthropocene fragmentation influence genetic variation in the Illinois state–listed mottled sculpin (Cottus bairdii). Environmental Biology of Fishes, 1-18.
- Corush, J. B. (2024). Nest-Associating Minnows Prefer Occupying Longear Sunfish Nests Over Green Sunfish Nests. Northeastern Naturalist, 31(4), 479-487.
- Cucalón, R. V., Corush, J. B., Niemiller, M. L., Curtis, A. N., Hart, P. B., Kuhajda, B. R., ... & Tan, M. (2024). Population genomics and mitochondrial DNA reveal cryptic diversity in North American Spring Cavefishes (Amblyopsidae, Forbesichthys). Conservation Genetics, 25(6), 1283-1301.
- Corush, J. B., Pierson, T. W., Shiao, J. C., Katayama, Y., Zhang, J., & Fitzpatrick, B. M. (2022). Amphibious mudskipper populations are genetically connected along coastlines, but differentiated across water. Journal of Biogeography, 49(4), 767-779.
- Corush, J. B., Fitzpatrick, B. M., Wolfe, E. L., & Keck, B. P. (2021). Breeding behaviour predicts patterns of natural hybridization in North American minnows (Cyprinidae). Journal of Evolutionary Biology, 34(3), 486-500.
- Corush, J. B. (2019). Evolutionary patterns of diadromy in fishes: more than a transitional state between marine and freshwater. BMC Evolutionary Biology, 19(1), 168.
- Fitzpatrick, B. M., Ryan, M. E., Johnson, J. R., Corush, J., & Carter, E. T. (2015). Hybridization and the species problem in conservation. Current Zoology, 61(1), 206-216.
Current lab members:
- Paula Rodriguez - Masters Student
- Paula joined the lab in fall 2025. Paula is evaluating DNA extraction protocols to increase genetic yields from fish eggs.
Future lab members:
- I am accepting Ph.D. and Masters Students for fall 2026
- If you are interested in joining my lab, please email me with your CV and a paragraph about your interests related to my work.
I am recruting a Ph.D. (or Masters-to-Ph.D.) students to join my lab in Illinois Institute of Technology's Biology department starting Fall 2026!
I am open to students interested in a wide range of topics related to evolutionary biology, fish trait evolution, comparative phylogenetic methods, and population genetics. My lab uses a combination of molecular, analytical, and natural history methods. Some of the systems my lab focus on include:
1) Hybridization and breeding behavior evolution in North American minnows,
2) Biogeography and amphibious behavior evolution in mudskippers,
3) Invasive round goby population dynamics in the Great Lakes region.
IIT is in the heart of Chicago and the historic Bronzeville neighborhood. The Biology department is located a short walk from L stops on the Red and Green lines. My lab also has an affilieation with the Field Museums allowing access to collection and molecular lab space.
If you are interested in the above topics (in fishes or other organisms), or in topics related to my previously published papers, please reach out with a brief description of your interests and a CV.
Teaching
- Molecular Biology ((BIOL 515) - Fall 2025
- Urban Evology ((BIOL 200) - Spring 2026
- -Conservation of ‘extinct’ species (IB546) - graduate seminar.
- --Phylogenetic Comparative Methods (IB546) - graduate seminar. (co-instructer)