Mucous membranes are involved in approximately 50% cases.
In contrast, when hosts are dexamethasone-treated the mucous cell discharge is inhibited whereby the total cell count increases significantly accompanied by a reduced response.
The worm feeds by drawing a plug of tissue (epithelial cells, blood cells and mucous) into the buccal cavity.
The progressive digestion of the ingested plug of tissue (epithelial cells, blood cells and mucous) was visualized.
The present study shows that the density of mucous cells is rather plastic, and can change rapidly during infection.
In this context it is possible that parasite reproduction could be triggered by an increased number of undischarged mucous cells in the microhabitat.
Thus, the drug induced inhibition of mucous cell function could be one of more factors explaining the corticosteroid labile resistance of salmonids to gyrodactylid invasion.
Thus, it can be suggested that infection stimulates mucous cell production and immediate mucus discharge in untreated fish with an effective anti-parasitic response.