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Instream habitat degradation and loss are major threats to freshwater fishes and critical conservation issues among nongame species due to a lack of research and knowledge concerning their habitat requirements. Instream physical cover is an important component of fish habitat, especially for benthic species that require cover for reproduction and shelter from predators. One such species is the Carolina Madtom Noturus furiosus, a small, imperiled, nongame catfish that is endemic to the Neuse and Tar River basins of North Carolina. To enhance understanding of instream cover dynamics, we constructed artificial cover units from terra cotta materials and deployed them in rivers to (1) evaluate whether they could be an effective passive-sampling technique to estimate detection and occupancy of the Carolina Madtom and (2) determine their potential to enhance habitat in systems where instream cover has been lost. Artificial cover units were deployed at eight sites in the Neuse and Tar River basins, and the units collected 30 Carolina Madtoms at two sites in the Tar River basin. Occupancy modeling estimated a Carolina Madtom detection probability of 0.92 using artificial cover units. Compared to other standardized sampling methods, artificial cover units were an efficient passive-sampling technique for detecting Carolina Madtoms. Observations also revealed that artificial cover units were occupied by Carolina Madtoms for reproduction. These findings provide an additional means by which natural resource managers can assess the status of this imperiled species via an inexpensive passive-sampling device that can provide spawning habitat and protection from predators as well as helping to mitigate the effects of instream habitat degradation.

The crayfish genus Orconectes is widespread in North America and includes both regional endemics and several aggressively invasive species. Orconectes rusticus was recently discovered in three western North Carolina streams. We examined specimens from these localities as well as individuals from across the region using molecular and morphological analyses to verify diagnoses. We sequenced and analyzed a portion of the cytochrome c oxidase subunit (COI) gene and compared reads to GenBank reference sequences. We used mtDNA diagnoses to evaluate the utility of quantitative morphological analyses to correctly classify specimens. Comparisons with reference sequences revealed cryptic diversity among introduced populations. The population previously identified as O. rusticus in the Little Tennessee River is genetically most similar to O. juvenilis. Moreover, the putative un-described Cheoah Crayfish appears to be an introduced O. juvenilis population. Comparisons with topotypic and introduced O. juvenilis populations suggest the Little Tennessee River population originated in the lower Ohio Valley and that populations of this cryptic invader may be more widespread than previously believed. Additionally, these results demonstrate the susceptibility of reservoir fisheries to crayfish invasions. Future studies of invasive crayfish and putative new species should use molecular data to verify morphological diagnoses.

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Identification and conservation of genetic diversity within and among freshwater fish populations are important to better manage and conserve imperiled species. The Carolina Madtom Noturus furiosus is a small, nongame catfish that is endemic to the Tar and Neuse River basins of North Carolina. Genetic structure has not been studied in the species, and given recent population declines in both basins, identification of remaining genetic diversity within the species is vital for informing conservation efforts. To assess the status and trends of Carolina Madtom genetic

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