Abstract
Two endemic Texas crayfish species (Procambarus nigrocinctus and Procambarus nechesae) are listed as Species of Greatest Conservation Need (SGCN) by the Texas Parks and Wildlife Department. There is little known about their life history and current distribution as they have only been sampled twice since their description in 1990. In an effort to inform about best sampling practices this project developed an environmental DNA (eDNA) assay for both target species. There are many aspects of eDNA sampling that have not been standardized due to it being a relatively new tool in conservation biology. For example, DNA shedding may be affected by seasonality due to changes in abiotic and biotic factors which could affect positive eDNA detection rates. This project aimed to compare the efficacy of water and sediment eDNA techniques with live capture sampling throughout one year (January – December 2025). In this study we created a novel species – specific multiplex ddPCR assay, and a successful water eDNA protocol showing 18 positive combined samples out of 55 samples. In contrast, the sediment eDNA protocol failed to produce positive samples. Live capture sampling resulted in a total of 1,594 individuals and 60 water quality measurements throughout the sampling year. Using these data and logistic regression models, we found that individuals caught + pH is the best model for predicting eDNA detection. Overall, eDNA remains a useful tool for survey practices and should be implemented along with live capture techniques to best optimize sampling efforts.
Date of publication
Summer 6-29-2026
Document Type
Thesis
Language
english
Persistent identifier
http://hdl.handle.net/10950/5082
Committee members
Dr. Matthew J. Greenwold, Dr. Katrin Kellner, Dr. Joshua Banta, Dr. Archis Grubh
Degree
Master of Biology
Recommended Citation
Blow, Matthew J., "COMPARING THE EFFECTS OF SEASONALITY ON CRAYFISH EDNA DETECTION" (2026). Biology Theses. Paper 99.
http://hdl.handle.net/10950/5082