Rapid heat hardening in embryos of the lizard Anolis sagrei

Adaptive thermal tolerance plasticity can dampen the negative effects of warming. However, our knowledge of tolerance plasticity is lacking for embryonic stages that are relatively immobile and may benefit the most from an adaptive plastic response. We tested for heat hardening capacity (a rapid increase in thermal tolerance that manifests in minutes to hours) in embryos of the lizard Anolis sagrei. We compared survival of a lethal temperature exposure between embryos that either did (‘hardened’) or did not (‘not hardened’) receive a high but non-lethal temperature pre-treatment. We also measured heart rates at common garden temperatures before and after heat exposures to assess metabolic consequences. ‘Hardened’ embryos had significantly greater survival after lethal heat exposure relative to ‘not hardened’ embryos. That said, heat pre-treatment led to a subsequent increase in embryo heart rate that did not occur in embryos that did not receive pre-treatment, indicative of an energetic..., Approximately 300 female A. sagrei were collected from Miami-Dade County, FL during May of 2022 and transported to Loyola University Chicago, where they were housed following established protocols. Briefly, females were housed in groups of up to 6 individuals per cage with perches and moist potting soil available for egg laying [16, 37]. Crickets are provided daily as food and enclosures are misted with water five or six times per day with an automatic misting system (MistKing, Jungle Hobbies Ltd.). Eggs were collected daily between 900 and 1000 h and were incubated at 27°C, within the natural range of A. sagrei nests [16, 38], in a sealed petri dish filled with moist vermiculite (-150 kPa)[16]. Given that multiple females were housed together, we could not determine the source of each egg. However, we assume that each egg was from a different female due to our sampling design: A. sagrei lay one egg at a time at an interval of 7-10 d, and all eggs used in the study (N = 89) were collect..., Data are a .csv file that can be opened with Excel or other similar software.