Cryolaternula elliptica
All animals used in experimental work were collected at Rothera Research Station, Adelaide Island, Antarctic Peninsula (67o 34׳ 07״ S, 68o 07׳ 30״ W) by SCUBA divers during the austral summer at depths of 10-15m. The animals were immediately returned to the laboratory where they were maintained in a through-flow aquarium with a temperature of 0.6*0.3oC, under a simulated natural light:dark cycle. All animals were mature adults, with a range of shell sizes between 50.1-83.5mm. As shell length is related to animal age: surface aging estimates using growth rings produced an mean age of  8.3 years (SE mean 0.207) with a range from 6-14 years, with a median of 8 years. Mantle tissue was dissected from the animals and immediately flash frozen in liquid nitrogen for later RNA extraction.