Effect of Cestodal Infestation on the Distribution Pattern of Digestive Enzyme Activities along the Small Intestine of the Kittiwake (<Emphasis Type="Italic">Rissa tridactyla</Emphasis>)

Activities of digestive enzymes in the intestine of adult and nestling kittiwakes (Rissa tridactyla) were studied. Glycosidase and protease activities in the three parts of the small intestine (proximal, medial and distal) as well as their total activity were determined, and the glycosidase/protease activity ratio (G/P coefficient) was calculated. Enzyme activities were found to be distributed unevenly along the intestine. In a proximal to distal direction, glycosidase and protease activities decrease in nestlings and increase in adult kittiwakes. In nestlings, protease activity values are several times higher than in adults. G/P coefficient values vary within the range of 0.33–0.92 in adult animals and 0.22–0.41 in nestlings. Infestation with tapeworms Alcataenia larina (Cestoda, Dilepididae) and Tetrabothrius erostris (Cestoda, Tetrabothriidae) leads to reduced digestive enzyme activities in the small intestine of kittiwake nestlings. In adult animals, infestation with T. erostris leads to a reduced and with A. larina to an increased protease activity.