In fish, only a fewstudies have quantified the effects of intestinal helminth
infection on the density of mucous cells and on the composition
of the mucus [17] and [18]. The main aim of the current investigation
was to compare the distribution and type of intestinal mucous cells
found in uninfected chub, Squalius cephalus, and in individuals infected
at different distances from the parasite P. laevis.