Date of Defense


Date of Graduation



Biological Sciences

First Advisor

Monica McCullough

Second Advisor

Tanya Timmerman

Third Advisor

Julie VanGyseghem


The nervous system of crayfish, a freshwater crustacean, is largely regulated by the flow of calcium (Ca2+) ions in a cell across a concentration gradient that produces electrical impulses and controls movement (Krause et al., 1998). Crayfish obtain Ca2+ from their external aquatic environment. Therefore, rapid changes in the concentration of Ca2+ in freshwater environments may cause negative impacts to the neural system of crayfish and subsequently the freshwater food chain. These impact of altered Ca2+ levels may create hyperactive or hypoactive movement due to over-, under-stimulation, respectfully in the skeletal muscle of the crayfish, which may alter the of growth and survival of these animals. As these unique freshwater environments are dependent upon climate change in the surrounding atmosphere, the Ca2+ present in freshwater environments is also regulated by external factors such as temperature and exposure to sunlight (Betini et al., 2016; Hammond et al., 2005). The aim of this literature review is to compare how climate change, a global crisis, can disrupt regular crayfish neural functions and interrupt the freshwater food chain. Varying temperatures, acid rain, and heavy metals are considered to influence aquatic Ca2+ levels to the greatest extent. Other considerations scientists have proposed includes the idea of temperature being the limiting factor in extinction rates of crayfish and other freshwater crustaceans rather than Ca2+ levels (Hammond et al., 2005). Here, I will discuss the effects of altered of Ca2+ levels in different freshwater environments on the crayfish neural system and a durational effect of rising pollution levels as predictions of the food chain repercussion. As climate change adversely impacts the nervous system of crayfish, it also contributes to extinction rates and lack of thermal tolerance in crustaceans (Kelly et al., 2011). Not only do humans rely on crayfish as a food source, but also as a model organism to help develop medications and vaccines for new diseases.

Access Setting

Honors Thesis-Open Access

Presentation.pdf (1939 kB)
Defense Presentation