A review of freshwater species of Diphyllobothrium with redescriptions and the distribution of D. dendriticum (Nitzsch, 1824) and D. ditremum (Creplin, 1825) from North America

Abstract

Plerocercoids of Diphyllobothrium were studied from fish samples representing eight species of salmonids from British Columbia, Wyoming, Quebec, and Maine. Adults were studied mainly from experimental infections of golden hamsters, Mesocricetus auratus (Waterhouse). Using scanning electron microscopy and histological techniques, the plerocercoids and adults were identified as Diphyllobothrium dendriticum or Diphyllobothrium ditremum. Morphological comparisons were made with European specimens of these two species and those of Diphyllobothrium latum (Linnaeus, 1758). Among the nine freshwater species reviewed, Diphyllobothrium cordiceps (Leidy, 1872), Diphyllobothrium sebago (Ward, 1910), and Diphyllobothrium ursi Rausch, 1954, are considered synonyms of Diphyllobothrium dendriticum.