Revisiting Hunterella nodulosa Mackiewicz and McCrae, 1962 (Cestoda: Caryophyllidae) from Catostomus commersoni (Lacépède) with a Special Treatment of its Ecological Diversity in Wisconsin Waters

Abstract

Specimens of Hunterella nodulosa Mackiewicz and McCrae, 1962 (Caryophyllidae) were first collected in SE Wisconsin from the white sucker Catostomus commersoni (Lacépède) in Tichigan Lake and the Root and Pike rivers. We update our first and only 1986 account of these Wisconsin populations from Tichigan Lake, with new observations and measurements, and compare them with those in the original and other descriptions. The morphology of H. nodulosa is revisited using light microscopy revealing new features. Emphasis is placed on the morphological variability of its unusual scolex and reproductive structures with variable ovarian shapes using many microscopic images depicting real-life forms. Measurements of 10 specimens and the re-examination of 12, 85, and 33 more specimens from Tichigan Lake, Root River, and Pike River for the first time, respectively provided an opportunity to review the taxonomy and description of the species, distinguish morphometric locality differences, and correct and update other statements and concepts by other observers. The disconnected distribution of worms from the same host species in separate waters within Wisconsin and in various states may be related to the disjunct post-glacial distribution of their primary hosts.