Meeting Abstract
Mitochondria are thought to have a biphasic response to the production of reactive oxygen species (ROS), where low levels of ROS benefit mitochondrial performance and high levels are damaging. Based on a previous study that showed a significant increase in ROS production under three-hour UV-B exposure in Antarctic and temperate copepods, we hypothesized that such a moderate oxidative event leads to more advantageous life history characteristics. Using UV-B light as an oxidant to induce moderate ROS production in Tigriopus californicus copepods, we measured the impact of UV-B exposure on fecundity and longevity in female copepods. Treatments included an unexposed control and both one and three-hour UV-B exposure (0.5 W/m2) during mate guarding. We found that moderate UV-B exposure resulted in higher fecundity, associated with an increase in size of the first clutch, and a decrease in longevity among all females that mated. UV-B exposure had no effect on whether females produced clutches. Gestation duration and size of the first clutch were inversely related. Females that did produce clutches lived longer, and among breeding females, the number of clutches that a female produced increased with her longevity. UV-B exposure had no significant effect on gestation duration of the first clutch or on the number of clutches that a female produced. These findings indicate a benefit to moderate UV-B exposure, where individuals exposed to moderate oxidation may have an increased capacity to reproduce, at least early in their reproductive life.
