USAP-DC

Antarctic marine ectotherms exhibit universally slow growth, low metabolic rates, and extended development, yet many of their rate processes related to physiology and metabolism are highly thermally sensitive. This suggests that small changes in temperature may result in dramatic changes to energy metabolism, growth, and the rate and duration of development. This project will measure the effects of temperature on metabolism, developmental rate, and the energetic cost of development of four common and ecologically important species of benthic Antarctic marine invertebrates. These effects will be measured over the functional ranges of the organisms and in the context of environmentally relevant seasonal shifts in temperature around McMurdo Sound. Recent data show that seasonal warming of ~1°C near McMurdo Station is accompanied by long-lasting hyperoxic events that impact the benthos in the nearshore boundary layer. This research will provide a more comprehensive understanding of both annual variation in environmental oxygen and temperature across the Sound, and whether this variation drives changes in developmental rate and energetics that are consistent with physiological acclimatization. These data will provide key information about potential impacts of warming Antarctic ectotherms. In addition, this project will support undergraduate and graduate research and partner with large-enrollment undergraduate courses and REU programs at an ANNH and AANAPISI Title III minority-serving institution. We have completed one of our two scheduled field and data-collecting seasons, but our research was put on hold by COVID and by equipment and sea ice conditions at McMurdo. We have established baseline information on energy utilization by embryos of several species under ambient conditions and early data suggest that metabolism is highly affected by temperature in the range of -2.0 C to 1 C, and less so thereafter.

Person	Role
Moran, Amy	Investigator and contact

Antarctic Organisms and Ecosystems

Award # 1745130

USAP-1745130_1

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	Video of Colossendeis megalonyx behavior around egg mass	MP4	exists
USAP-DC	Egg diameters of Colossendeis megalonyx	Excel	exists

1. Woods, H. A., & Moran, A. L. (2020). Reconsidering the Oxygen–Temperature Hypothesis of Polar Gigantism: Successes, Failures, and Nuance. Integrative and Comparative Biology. (doi:10.1093/icb/icaa088)
2. A.L. Moran, M-W.A. Toh, G.T. Lobert, T. Ely, P.B. Marko. Egg masses and larval development of the Antarctic cephalaspidean slug Waegelea antarctica, with notes on egg masses of the related Antarctophiline alata. In press at Journal of Molluscan Studies.