Fig. 2

Proximal intestine histological sections of fish fed different test diets. A CF diet, well preserved intestinal morphology with elongated and regularly branched complex villi. B FH10 diet, similar to the CF diet, intestinal morphology was well preserved with elongated and regularly branched complex villi. C CV diet, elongated, irregularly branched complex villi with extensive multifocal detachment of lamina epithelialis from the lamina propria (arrows). D Detail of area indicated by the rectangle in panel C; note the pronounced vacuolisation of enterocytes (arrow heads) and notable number of neutral goblet cells (NGC). E VH10 diet, elongated, irregularly and highly branched complex villi with multifocal moderate to extensive detachment of lamina epithelialis from the lamina propria (arrows). F Detail of area indicated with by the rectangle in panel E; note the moderate vacuolisation of enterocytes (arrow heads) with the predominance of acid goblet cells (AGC) over neutral goblet cells (NGC). G VH10P30 diet, elongated and irregularly branched complex villi with multifocal moderate to extensive detachment of lamina epithelialis from the lamina propria (arrows). Alcian blue/PAS staining, pH = 2.5. Scale bar: A, B, C, E, G = 500 μm, D, F = 100 μm