HELMINTHS OF RAINBOW SMELT, OSMERUS-MORDAX, FROM 5 LOCALITIES IN LAKE HURON AND LAKE-MICHIGAN, WITH EMPHASIS ON DIPLOSTOMUM-SPATHACEUM

A total of 428 smelt, Osmerus mordax (family: Osmeridae), was collected from 4 Michigan localities associated with Lake Huron and from 1 indiana locality in southern Lake Michigan. Seven helminth species (1 Digenea, 3 Cestoda, 2 Nematoda, 1 Acanthocephala) were found in spawning smelt sampled in April 1984, 1985, and 1986. At least 97% of the smelt from each locality was infected with 1 or more helminthus. Diplostomum spathaceum, Eubothrium sp., Cystidicola sp., and Echinorhynchus salmonis infected smelt from all localities. Cyathocephalus truncatus is reported from smelt for the first time. THe helminth faunas of smelt from all localities were numerically dominated by D. spathaceum and E. salmonis. THe lens of the right eye of smelt from all localities had a higher mean intensity of D. spathaceum than did the left lens; these right lens-left lens differences were statistically signifiant from 2 localities. Diplostomum spathaceum exhibited significant asymmetry between lenses in 21 (15%) female and 29 (10%) male smelt.