Kentucky Journal of Undergraduate Scholarship

Project Title

Adaptive Tolerance to Sodium Chloride in Daphnia magna

Authors

Brady P. Parlato, Georgetown CollegeFollow
Rick Kopp, Georgetown CollegeFollow

Domain

Life Sciences

Abstract

Salinity levels of some freshwater systems have been altered by humans, posing a threat to aquatic life. We hypothesized that a Daphnia magna population pre-treated with a low concentration of NaCl would develop greater salinity tolerance than an untreated population. Two Daphnia magna cultures with 60 individuals each were established, one started with 1.00 ppt NaCl and increased by 0.20 ppt weekly, and the other with pure spring water. After 4 weeks, 40 neonates from each culture were individually placed in a solution of 2.30 ppt NaCl (separately determined to be the LC₅₀) for 48 hours. Survival was significantly greater for the experimental group (LR = 7.5, df = 1, P < 0.05) and significantly exceeded the expected 50% survival rate (χ² = 6.4, df = 1, P < 0.05). This finding suggests that Daphnia populations can evolve or acclimatize to increase their survival in high salinity habitats.

Mentor Name

Dr. Rick Kopp

Mentor Email

Rick_Kopp@georgetowncollege.edu

Recommended Citation

Parlato, Brady P. and Kopp, Rick (2020) "Adaptive Tolerance to Sodium Chloride in Daphnia magna," Kentucky Journal of Undergraduate Scholarship: Vol. 4: Iss. 1, Article 2.
Available at: https://encompass.eku.edu/kjus/vol4/iss1/2