The American Brook Lamprey Lethenteron appendix is a state threatened species found
in large clear creeks in northeastern Illinois. The free-swimming adult stage is short, spawning, and dying shortly thereafter. The larval stage can last more than 5 years, during which the larva burrows in sandy, silty substrate with only its head exposed. This
life history makes detecting them with traditional survey methods difficult. For this reason, another of our early eDNA projects focused on detecting the American Brook Lamprey. Our lab tests found our primer for the American Brook Lamprey amplified DNA
of the correct species (INHS 2019:13). This listed species can now be more easily surveyed by collecting water samples from suitable habitat and analyzing for shed DNA.
Understanding the relative influences of habitat needs and biotic interactions is critical for conserving fishes imperiled by anthropogenic disturbances. This is especially true for unique and sensitive ecosystems like glacial lake habitats, which occur in northeastern Illinois in urbanized areas. In Illinois, these lakes contain a unique fish fauna that includes several rare species, the state endangered Pugnose Shiner Notropis anogenus and Blacknose Shiner Notropis heterolepis, the state threatened Blackchin Shiner Notropis heterodon, Western Banded Killifish Fundulus diaphanus menona, and Starhead Topminnow Fundulus dispar, as well as the recently delisted Iowa Darter Etheostoma exile. We collected samples at 8 sites and used an environmental DNA metabarcoding approach to determine occupancy of these rare fishes, along with compiling other fish community information, at each site. We modeled habitat and biotic characteristics to glacial lake fish occupancy using Hurdle models. Our results suggest an environmental DNA metabarcoding approach provided adequate information on rare species presence and community assemblages in urbanized glacial lake habitats in northeastern Illinois.
