Revista Chilena de Historia Natural 84 (2): 195-201, 2011
Parent-to-offspring transfer of sublethal effects of copper exposure: Metabolic rate
and life-history traits of Daphnia
In ecological communities, pollution driven perturbations exert immediate
effects on sensitive individuals, but these effects may be transmitted among interacting organisms and spread over the
community through several paths. This makes the assessment and prediction of ecological consequences of pollution
difficult. The propagation of perturbation effects among organisms can be horizontal among organisms that coexist in
space and time, and vertical among organism that belong to different generations. The latter process is poorly understood,
in particular in planktonic organisms facing metal pollution. In this study we evaluate the vertical transfer of effects driven
by sublethal copper stress on the heartbeat rate, somatic growth and fertility of Daphnia pulex. In order to
evaluate this, we performed a factorial experiment in which parental and filial generations were exposed to both
copperenriched and control media. We found that parental exposure to copper exerted a significant effect on the heartbeat
rate, somatic growth and fertility of offspring, revealing a transgenerational effect in D. pulex. This response
may be explained by a higher resource investment on repair/detoxification processes in the parental generation, allocating
fewer resources to offspring quality. Our results suggest that responsiveness of organisms to stress is dependent on parental
history.
Key words:
ecotoxicology,
heartbeat rate, maternal effects, transgenerational effects, zooplankton
