Abstract The red macroalgae Palmaria palmata is rich in protein and bioactive compounds and has been identified as a promising dietary ingredient for aquafeeds, with the potential to partially replace selected plant-based feed components. A digestibility trial and a growth trial were conducted to evaluate the potential of untreated and pretreated P. palmata as feed ingredients for juvenile European seabass ( Dicentrarchus labrax ), with initial body weights of 63.2 g and 38.0 g, respectively. Fi