Fig. 1.

Lesions induced by M. hirudinaceus in wild boar: a a fibrotic nodule caused by the attachment of worm proboscis to the intestinal wall, visible from serosal surface, b local trauma and hemorrhages around the site of the worm’s head invading the intestinal tissue in the early stages; c adult worm embedded in the intestine wall, d head of juvenile worm penetrated the tissue, e anterior of acanthocephalan embedded in the intestinal wall demonstrates the protractible proboscis with its hooks (×40, H&E), f parasite penetrates into the deep layers of the intestine, causes severe necrosis and ulcer with heavy inflammatory cell infiltrations (×40, H&E)