The effects of increasing temperature owing to thermal discharge and global warming on zooplanktons such as Daphnia magna are a growing concern. The purpose of this study was to evaluate the effects of elevated temperature (25 °C) on oxidative stress responses, growth, and reproduction of D. magna across 10 generations. The number of offspring per female at 21 d was significantly increased and the rate of adult somatic growth (5–21 d) was decreased in the F0 generation at 25 °C compared with those at the reference temperature 20 °C. However, the F3 generation showed the lowest number of offspring and the highest adult somatic growth rate and oxidative stress responses (5 d) at 25 °C. Moreover, all life-history traits seemed to recover to the levels of the control group from the F6 generation at 20 °C. These findings suggest that D. magna under continuous thermal stress exhibits non-adaptive responses in the early generations (F0–F3) and changes to adaptive responses in the later generations (F6–F9). However, the underlying epigenetic mechanism should be identified in the future.
Bibliographical noteFunding Information:
This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korea government ( NRF-2016R1A2B4016299 and NRF-2019R1A2C1002890 ).
© 2020 Elsevier Inc.
- Life history
- Oxidative stress
- Somatic growth
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health
- Health, Toxicology and Mutagenesis