Transcriptomic analyses were undertaken on both in situ collected and experimentally warmed blue mussels (Mytilus edulis) from Greenland. M. edulis were collected from the Godthabsfjorden near Nuuk, Greenland (64.45555, -51.14416) at the following locations and dates: Inner fjord (64.45941, -50.31030) on 11/06/2018; outer fjord (64.19666, -51.69) on 13/06/2018, and sub-tidal (64.19666, -51.69) on 13/06/2018 (outer fjord at 20-40cm below the lowest low water mark). The in situ collected inner and outer fjord intertidal animals with outer fjord subtidal animals used as controls were collected at 27 degree Celsius, 19 degree Celsius and 3 degree Celsius, respectively. Some of the outer fjord subtidal M. edulis were experimentally warmed to 22 degree Celsius and 32 degree Celsius for one hour to mimic high aerial exposure temperatures in the inner and outer fjord intertidal, respectively. RNA-Seq was performed on 5 animals for each treatment, with all subsequent bioinformatics analyses performed by Novogene, China. This work was supported by the Carlsberg Foundation, the Independent Research Fund Denmark (Danmarks Frie Forskningsfond) (DFF-International Postdoc; case no. 7027-00060B), a Marie Sklodowska-Curie Individual Fellowship (IF) under contract number 797387 and Aage V. Jensens Fond (Aage V. Jensens Foundation) and NERC-UKRI core funding to the British Antarctic Survey.

This is a physiological dataset for the Southern Patagonian limpet, Nacella deaurata. The limpets were collected from 2-6m depth in the Straits of Magellan near to Punta Arenas (53.164 S, 70.917 W) between Nov and the end of Jan 2018-19. A 2 month feeding experiment maintained N. deaurata at 1,4,8,11 and 14 degree Celsius for 2 months. Ingestion rate, absorption efficiency, absorption rate, oxygen consumption (uptake), scope for growth and mortality were measured. The thermal reaction norm for duration tenacity of field fresh subtidal and intertidal limpets, as well as subtidal limpets that were incubated at 8 degree Celsius for 2 months was investigated. The thermal reaction norm of radula scraping rates of field fresh limpets was measured. This work was funded by the Center FONDAP-IDEAL 15150003, ANID Chile and NERC core funding to the British Antarctic Survey.