intestinal morphology, decreased intestinal digestive and absorptive enzyme activities, and caused 37 poor nutrient digestibility and growth performance in juvenile largemouth bass. In fact, the adverse 38 effects of guar gum are closely related to its viscous level, and high viscous guar gum adversely 39 affects the rearing performance of juvenile largemouth bass. 40 41In addition to the above-mentioned fish species, two investigations were conducted on Pacific white 42 leg shrimp (Litopenaeus vannamei), considered the most important farmed crustacean species. of P. f. martensii was higher than that of P. maxima. Irrespective of the microalga species, RGR was 124 higher when fed with a microalgae bend than with a single microalga. Amylase, cellulase, lipase, and 125 pepsin activity was higher in P. f. Martensii than with P. maxima fed with the same diets. 126 127The papers presented in this Research Topic and conducted on diverse species highlight the 128 usefulness of the physiologic approaches to deepen knowledge in feeding farmed aquatic organisms. 129This helps fish nutritionists to tailor and improve the nutritional profile of the diet and hence to 130 provide more adequate and healthy diets for fish. We sincerely thank all authors and reviewers for 131 their valuable contribution that made the publication of this Research Topic possible. 132
Author Contributions 133
