Parasites of the alimentary tract of European otters in Bory Tucholskie National Park

Abstract

The aim of the study was to investigate the intestinal parasites of European otters (Lutra lutra) living in Bory Tucholskie National Park. The park is located in northern Poland, in the Pomeranian Voivodeship. From June to October 2019, 300 fecal samples were collected on the banks of 10 lakes and the Struga river within the national park. The samples were kept at 4°C for a maximum of 3 weeks until examination. Standard flotation (in sodium chloride aqueous solution) and sedimentation methods were used. The total percentage of positive samples containing parasites of the alimentary tract amounted to 15.3% (46 samples). Oocysts Cystoisospora gottschalki were found in 6.7% of samples, trematode eggs (Opisthorchis sp., Metorchis sp. and/or Pseudamphistomum truncatum, Alaria alata and/or Isthmiophora melis) in 4.3%, cestode eggs of the family Diphyllobothridae in 2.0%, and eggs of nematodes (Strongyloides lutrae, Aonchotheca putori, Uncinaria sp.) in 3.7% of samples. Two species, C. gottschalki and S. lutrae, were found in Poland for the first time. The large variety of parasite species is evidence of well-preserved local ecosystems.