The Peculiarities of Parasiting of Polymorphus phippsi (Palaeacanthocephala: Polymorphidae) in the Intestines of Seabirds from the Barents Sea

Aspects of the localization and digestion physiology of the acanthocephalan Polymorphus phippsi (Kostylew, 1922) (Palaeacanthocephala: Polymorphidae) from the intestines of seabirds (common eider Somateria mollissima (Linnaeus, 1758), king eider Somateria spectabilis (Linnaeus, 1758), and herring gull Larus argentatus (Pontoppidan, 1763)) from various regions of the Barents Sea, as well as its relationships with the final hosts, have been studied. It has been revealed that P. phippsi parasitizes in the distal section of the small intestine of birds. The infestation intensity of P. phippsi is 82 ± 35.2 (5–282) individuals for common eider, 31.5 ± 18.9 (1–115) for king eider, and 2.4 ± 0.4 (1–4) individuals for herring gull chicks. Membrane digestion processes involving proteases and glycosidases have been recorded on the surface of the tegument of P. phippsi . It is shown that the protease activity increases at attachment sites of the parasite in the intestinal mucosa of birds and the intensity of processes of cavity and membrane digestion involving proteases and glycosidases increases.