Fig. 1

Evaluation and scoring system used to assess histological parameters of gilthead seabream foregut. a Measurements performed in a foregut histological section (20×). b Detail of villi with a certain grade of infiltration of the lamina propia and the epithelia. Enterocytes nuclei were displaced in some cases. Epithelial vacuolization can also be observed in a normal grade (40×). c Enterocytes showed aligned nuclei in a basal position. Villi presented a low grade of infiltration of their lamina propia and of the epithelia, and low vacuolization. A certain grade of infiltration in the submucosa layer can be observed (20×). SL, ML, SML, VL, VT and number of GC were measured six times per section, and averages were obtained for each section (six sections per group, n = 6). V, EN, EI, LPI and SMI were assessed in each section (n = 6) using the following scoring system: V, normal (1) to hypervacuolated (4); EN, basal (1) to apical (4); EI, low (1) to markedly increased (4); LPI, low (1) to markedly increased (4); SMI, low (1) to markedly increased (4). SL, serous layer; ML, muscular layer; SML, submucosa layer; VL, villi length; VT, villi thickness; LP, lamina propria; GC, goblet cells; V, supranuclear absorptive vacuoles; EN, enterocytes nuclei; EI, epithelial infiltration; LPI, lamina propria infiltration; SMI, submucosa infiltration