1. We collected data on metabolic activity and growth in pectinid bivalves from published studies. The resulting database comprised three types of datasets: (i) synoptic data (13 populations, 7 species), where both individual growth performance and metabolism are known, (ii) metabolism only data (82 populations, 13 species), and (iii) growth only data (198 populations, 26 species).2. In pectinid bivalves belonging to different species and living under different environmental conditions metabolic activity (standard metabolic rate, SMRAvg, Q10 = 2.28) is more closely related to temperature than individual growth (overall growth performance, OGP index P, Q10 = 1.12).3. The synthesis of the two corresponding Arrhenius equations shows that the relationship between the SMRAvg-to-OGP ratio and temperature follows the Arrhenius model, too, with Q10 = 2.05.4. SMRAvg-to-OGP is an inverse proxy for growth efficiency, hence growth efficiency decreases with rising temperature across a wide range of pectinid populations and species. Thus, there is strong empirical evidence that elevated temperature constrains growth efficiency in scallops and that adaptation does not fully compensate for this effect.