Present address: Elena S. Barbieri, Ministerio de Educación de la Provincia del Chubut, Argentina.
Motility of Daphnia spinulata as Affected by Solar Radiation Throughout an Annual Cycle in Mid-latitudes of Patagonia†
Article first published online: 29 MAY 2007
Photochemistry and Photobiology
Volume 83, Issue 4, pages 824–832, July/August 2007
How to Cite
Gonçalves, R. J., Barbieri, E. S., Villafañe, V. E. and Helbling, E. W. (2007), Motility of Daphnia spinulata as Affected by Solar Radiation Throughout an Annual Cycle in Mid-latitudes of Patagonia. Photochemistry and Photobiology, 83: 824–832. doi: 10.1111/j.1751-1097.2007.00126.x
This invited paper is part of the symposium-in-print: UV Effects in Aquatic and Terrestrial Environments.
- Issue published online: 28 JUN 2008
- Article first published online: 29 MAY 2007
- Received 31 August 2006; accepted 26 February 2007; DOI: 10.1111/j.1751-1097.2007.00126.x
During an annual cycle, Daphnia spinulata collected from a plankton community of Patagonia was exposed outdoors to assess the impact of recently received solar radiation on motility (i.e. swimming speed and gravitaxis). Individual values of these parameters were obtained by video recordings and image analysis at different time intervals during the day. Initial swimming speed varied throughout the year, and changes in speed during exposure were not significantly affected by any waveband used in our experimental design (i.e. PAB, 280–700 nm; PA, 320–700 nm; and P, 400–700 nm). Overall, most of the individuals swam downwards, regardless of the radiation treatment imposed to the samples. We found that multifactor interactions (i.e. not a single parameter explained more than 40% of the observed variability) explained most of our observations on motility parameters. These factors include not only solar radiation, but other physical (underwater radiation field and wind intensity) and biological parameters (food availability, presence of predators and congeners). Our findings indicate that the plankton dynamics in the study site is likely to be governed by a sum of factors which must be taken into account when considering solar radiation effects on aquatic ecosystems.