New Perspectives on Isoglaridacris multivitellaria Amin, 1986 from the Lake Chubsucker Erimyzon sucetta (Lacépède) in Silver Lake, Wisconsin

Abstract

Specimens of Isoglaridacris multivitellaria (Caryophyllidae) were described from the posterior-most region of a lake chubsucker Erimyzon sucetta (Lacépède) in the land-locked Silver Lake, Wisconsin in November, 1978. All 4 adult specimens were found in one individual host and have never been reported again since. Specimens are distinguished from all others of the genus Isoglaridacris by their extensive post-ovarian vitellaria, and long distance between its cirrus sac and ovary. The cirrus sac is with concentric rings and the ovary is also characteristically follicular. The original description was well documented and included 9-line drawings. We describe and measure additional structures and include microscope images from all 4 specimens that clarify many of the features not readily presented with line drawings. The relic distribution of worms maybe related to the disjunct post-glacial distribution of their primary and only host, E. sucetta. We propose that I. multivitellaria may be found in the same host species elsewhere within its normal range of distribution