The Finding and Description of A Diverse Population of the Southern Cestode Isoglaridacris agminis Williams and Rogers, 1972 (Caryophyllaidae) from Lake Chub Sucker Erimyzon sucetta (Lacépède, 1802) in a Northern Land-Locked Lake in Wisconsin, with a Special Reference to its Disjunct Post-Glacial Distribution in North America

Abstract

Specimens of Isoglaridacris agminis Williams and Rogers, 1972 (Caryophyllidae) were first described from the lake chubsucker Erimyzon sucetta (Lacépède, 1802) in a small tributary of the Tallapoosa River at NE central Alabama. We have collected and examined I. agminis from the same host species in the land-locked Silver Lake, SE Wisconsin. We update our first and only 1986 account of this Wisconsin population, with new observations and measurements, and compare with those in the original and other descriptions. The morphology of I. agminis 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 throughout development using many microscopic images. Measurements of 17 specimens and the re-examination of 15 more specimens from Silver Lake provided an opportunity to review the taxonomy and description of the species, distinguish 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 of various states is attributed to the disjunct post-glacial distribution of their primary hosts.