With global climate change occurring at a more rapid pace than ever, it is important to assess how those environmental changes affect known sentinel species. Crayfish, although abundant in overall species numbers in North America (300+), may be considered a sentinel species because they are often found in niche habitats where slight changes have large consequences. As an adult, crayfish must first molt into a reproductive state to mate and reproduce. Once reproduction is complete, they will again molt out of this reproductive state but are still considered adults. Because pH has previously been shown to affect molting in crayfish, we chose to evaluate the effects of lowered pH on adult female and male Faxonius immunis molting in and out of their reproductive state (♂= Form 1/Form 2: ♀= Mature/Immature). Once female and male F. immunis reach adult size we will use a Delaware State University (DSU) aquaculture rack system to house four separate crayfish groups at four different pH levels. Females and males will be stocked randomly across systems with pH values: 4.5; 5.0, 6.0 and 7.0 (control). Observations and data collected will include reproductive form, molt frequency, and any molt malformations. It is expected that with long-term exposure to lower pH, both adult female and male F. immunis will not molt into their reproductive form. It is also expected that F. immunis held at a neutral (7.0) pH will molt into their respective reproductive form. Additionally, water quality will be monitored from the experimental system daily (O2, oC, pH) and analyzed weekly (NH3-N, NO2-N, calcium hardness).
Keywords: climate change, pH, crayfish, reproduction, molting
Acknowledgements: We acknowledge USDA NIFA CBG Award# 2023-38821-40369 “Providing Experiential Learning Opportunities and Extension Training in Aquaculture and Fisheries to Under-Served and Underrepresented Student Communities From 1890 Land Grant Institutions” for funding my internship and this project as part of the student experiential learning goal. We further acknowledge the Project Director, Dr. Gulnihal Ozbay for providing this internship opportunity and Dr. Dennis McIntosh for providing the space and resources at the DSU Aquaculture Research and Demonstration Facility to complete this project.