Meeting Abstract
The challenge of understanding how organisms will respond to global climate change is especially important in Antarctica where species have evolved for millions of years in a cold and thermally stable environment. In Antarctica, the combination of cold and highly oxygenated waters are thought to have allowed many benthic marine invertebrates to reach unusually large body sizes. However, if large body sizes are only viable in a context of stable high oxygen, cold temperatures, and correspondingly low organismal metabolic oxygen demand, polar giants may be disproportionately sensitive to warming temperatures. To test this hypothesis, we are investigating the interactions between temperature, size, and performance (measured as righting ability) in a family of Antarctic sea spiders (Pycnogonida, Colossendeidae). Individual sea spiders were tested for continuous righting ability at three temperatures (-1.8, 4, and 9 °C) and performance was measured as number of flips per hour. We used sea spiders with body masses (wet weight) ranging 0.21 to 15.17 g. In all size classes, performance at 4 °C did not differ from ambient (-1.8 °C) but performance significantly declined at 9 °C. However, large-bodied pycnogonids did not appear to be disproportionately affected by the high temperatures. Our research is continuing during the Antarctic spring, 2016. NSF PLR- 1341485.
