Protein hydrolysates from yeast and pig blood as alternative raw materials in microdiets for gilthead sea bream (Sparus aurata) larvae

► Yeast and pig blood protein hydrolysates were tested in diets for fish larvae. ► The quality of fish fed on these feeds was similar to that of fish fed live prey. ► Deformities in fish fed these feeds were lower in comparison to a standard feed. ► Tested raw materials promoted gut maturation in comparison to a standard feed. ► Amino acids (Leu, Phe, Val) affect fish larval skeletogenesis.