Abstract
As significant anthropogenic pressures are putting undue stress on the world's oceans, there has been a concerted effort to understand how marine organisms respond to environmental change. Transcriptomic approaches, in particular, have been readily employed to document the m RNA ‐level response of a plethora of marine invertebrates exposed to an array of simulated stress scenarios, with the tacit and untested assumption being that the respective proteins show a corresponding trend. To better understand the degree of congruency between m RNA and protein expression in an endosymbiotic marine invertebrate, m RNA s and proteins were sequenced from the same samples of the common, Indo‐Pacific coral Seriatopora hystrix exposed to stable or upwelling‐simulating conditions for 1 week. Of the 167 proteins downregulated at variable temperature, only two were associated with m RNA s that were also differentially expressed between treatments. Of the 378 differentially expressed genes, none were associated with a differentially expressed protein. Collectively, these results highlight the inherent risk of inferring cellular behaviour based on m RNA expression data alone and challenge the current, m RNA ‐focused approach taken by most marine and many molecular biologists.