Plants and animals – including marine invertebrates - acclimatize to stress conditions (Collier, Baumgard, Zimbelman, & Xiao, 2019; Demmig-Adams, Dumlao, Herzenach, & Adams, 2008; Foo & Byrne, 2016) and several recent studies show that heat acclimatization might help corals better withstand thermal stress and reduce the severity of coral bleaching and mortality (Bay & Palumbi, 2015; Bellantuono et al., 2012; Middlebrook, Hoegh-Guldberg, & Leggat, 2008; Palumbi et al., 2014; Schoepf et al., 2019), but this effect may be genotype-specific (Dilworth, Caruso, Kahkejian, Baker, & Drury, 2021). Unfortunately, this natural protection mechanism could be lost under future climate-change scenarios as seasonal temperature profiles change (Ainsworth et al., 2016).