Climate change has consequences over marine organisms and their behavior. Echinoderms have been found to be negatively affected on righting time, survival, feeding rate or growth by high temperatures, low salinity or their interaction. We analyzed the effects of temperature and salinity fluctuation under a climate change scenario on feeding rate, righting time and heat shock proteins (Hsp70) expression in the sea star Anasterias minuta. Our results showed negative effects of increased temperature in the feeding rate of A. minuta. In addition, Hsp70 expression in gonads showed an upregulation after water temperature increase in normal salinity conditions. Regarding the righting activity, we detected a variable pattern among treatments with significant statistical differences in the interaction of temperature and salinity, and in time intervals measured. Variations in sea stars feeding ecology could produce direct and cascading effects driving ecological shifts as changes in species composition of the coastal Patagonian ecosystems. Investigating the effect of sea stars on intertidal and subtidal assemblages in a climate change scenario is of great importance to provide valuable information for an adequate management of intertidal habitats, which have been little studied in Atlantic Patagonia. •Increasing temperature decreases the feeding rate of the sea star Anasterias minuta.•Righting activity of A. minuta showed statistical differences among treatments.•Interaction of temperature and salinity triggers an increased in Hsp70 expression.•Climate change will drive to direct and cascading effects on Patagonian coasts.