Parental Tetracycline Exposure Induces Genotoxic Damage and Fitness Deficits in Daphnia magna Offspring

Antibiotics contaminating aquatic environments is a challenge for the ONE Health initiative as it poses a risk to biodiversity. Tetracyclines are toxic to a wide range of organisms. The objective of this study was to assess the growth, individual fitness and DNA damage following a short-term exposure to tetracycline in Daphnia magna. Additionally, the long-term effects of DNA damage on population growth rate and individual fitness parameters in the offspring for intergenerations were evaluated. The results indicated that D. magna has a significant effect on tetracycline-induced fertility impairment, resulting in reduced survival and reproductive capacity of the parental groups and impaired growth and development of the offspring. Furthermore, tetracycline treatment resulted in a significant reduction in individual fitness, as evidenced by the significant reduction in maximum body length of D. magna in both tetracycline-exposed generations. D. magna was exposed to concentrations of 25, 50, 100, 200, and 400 mg/L for periods of 24-72 h, with the objective of determining the concentrations that would not be lethal and yet would induce DNA damage. Tetracycline concentrations of 50 and 25 mg/L did not result in excessive levels of cytotoxicity within 72 h. P, F1, and F1 offspring born between 48 and 72 h were tested for DNA damage. D. magna appears to recover from DNA damage, but concerns have been raised about using tetracycline repeatedly in water, as it can lead to higher concentrations and longer exposure times for lots of organisms.