Reducing the reliance of the aquaculture industry on wild fish resources remains a key challenge. Generally obtained from food coproducts, protein hydrolysates have emerged as promising functional and sustainable protein sources that can help compensate for the limitations of alternatives to marine proteins. In this study, we evaluated their use as a palatability enhancer (PE) by top-coating them directly on the feed, as a liquid and at low dose. We tested a PE made primarily from a shrimp liquid hydrolysate, as a cost-effective dietary solution to replace significant amounts of fish meal (FM) with plant proteins in juvenile red sea bream diets. The experimental feeds consisted in a high FM diet (HFM, 30% FM), a low FM diet (LFM, 15% FM) and two additional diets with 2% PE top-coated (HFM+PE and LFM+PE). Six replicate tanks, each containing fish weighing 27.2 ± 0.2 g, were provided with one of the test diets twice daily until apparent satiety for a duration of 15 weeks. Half of the tanks were exposed to an intermittent stress consisting in a 1 min net-chasing, 1 hour before their first meal. After the nutritional trial, individuals were subjected to an Edwarselia tarda challenge through injections. The basal diets, LFM and HFM, achieved comparable growth and feed efficiency. The use of LFM, therefore, mechanically reduced wild fish use by 25% if referring to the eFIFO index (Kok et al., 2020). PE supplementation in both diets resulted in enhanced fish growth and health performance, and improved feed use. Consequently, we estimated that PE use can significantly, and additionally, reduce by 6% the use of wild fish biomass in these conditions. The beneficial effects of PE on the growth performance were stable despite the stress challenge, which led however to overall strong reduction in growth performances in all groups. Survival was significantly increased by PE addition in response to the bacterial challenge compared to the LFM diet. All these results were supported by underlying physiological results. We concluded that liquid hydrolysate PE represent a great potential for feed formulators to cost-effectively reduce pressure on wild resources, while maintaining high performance of their feed.