TABLE 2.

Freshwater species of Diphyllobothriuma

SpeciesDefinitive hostSecond intermediate hostSite of infectionDistributionReferences
D. dalliae Rausch, 1956bDog, Arctic fox, occasionally humansAlaska blackfish, dolly vardenBody cavity (free)North America (Alaska)132, 134
D. dendriticum (Nitzsch, 1824)cFish-eating birds, especially gulls (Laridae); mammals, including humansSalmonid and coregonid fish (Salmoniformes)Usually viscera (free)Circumpolar (more northerly range than D. latum)9, 30, 134, 158, 166
D. latum (Linnaeus, 1758)dHumans (most suitable), terrestrial mammalsMainly pike, perch, burbot, char; less frequently ruff, pikeperch, yellow perchMusculature (free)Europe, North America (Alaska, Great Lakes), Asia27, 39, 134, 158
  • a Fish names are as follows: Alaska blackfish, Dallia pectoralis; burbot, Lota lota; char, Salvelinus alpinus; dolly varden, Salvelinus malma; perch, Perca fluviatilis; pike, Esox lucius; pikeperch, Sander vitreum; ruff, Gymnocephalus cernuus; yellow perch, Perca flavescens. Mammal names are as follows: Arctic fox, Alopex lagopus; dog, Canis familiaris.

  • b This species is a relatively common parasite of humans in western Alaska, where Alaska blackfish is frequently eaten raw or frozen by the Eskimos. Plerocercoids, but no human cases, were also recorded in eastern Siberia.

  • c It is probably the third most frequent causative agent of diphyllobothriosis in humans. The tapeworm is normally parasitic in birds and mammals but is quite frequently found in humans also. Plerocercoids are usually encysted on the viscera, but they were also found in the musculature (29, 39, 158). Synonyms are Diphyllobothrium fissiceps (Creplin, 1829); D. cordiceps (Leidy, 1872); D. exile (Linton, 1892); Sparganum sebago Ward, 1910; D. minus Cholodkovsky, 1916; D. canadense Cooper, 1921; D. strictum (Talysin, 1932); D. obdoriense Piotnikoff, 1933; D. nenzi Petrov, 1938; D. laruei Vergeer, 1942; D. oblongatum Thomas, 1946; D. medium Fahmy, 1954; D. microcordiceps Szidat et Soria, 1957; and D. norvegicum Vik, 1957.

  • d This is the most frequently found human-infecting species, but almost all cases reported as being caused by D. latum from Japan and South Korea, as well as many records from North America, may belong to other species, particularly D. nihonkaiense (see references 27, 72, 166, 169, 172, and 174). Records of D. latum from South America are questionable and should be confirmed using molecular markers. Synonyms are Taenia lata Linnaeus, 1758; Diphyllobothrium americanum Hall et Wigdor, 1918; D. tungussicum Podyapolskaya et Gnedina, 1932; and D. skrjabini Plotnikoff, 1933 (see reference 36 for other synonyms).