Parasites of Fish from the Great Lakes - Great Lakes Fishery ...

Protozoans
Of the protozoans, only one species of mastigophoran, Trypanosoma sp., has been reported from
fish. Two genera of ciliates, Trichodina and Capriniana, occurred on the gills of four fish species
(Table 3). The myxozoans are the most-common protozoan group based on the number of species
found (1 of Chloromyxum, 2 of Myxidium, 4 of Henneguya, 8 of Myxobolus, 1 of Thelohanellus,
1 of Zschokkella, 2 of Myxobilatus, and 1 of Sphaerospora). Most of these species are hostspecific
to a particular fish family. Only one microsporan species, Pleistophora sp., has been
reported from only one fish species, Myoxocephalus thompsonii.
Digenetic Trematodes
Thirteen species of adult trematodes representing six families have been reported. Many of these
species were reported from only one fish species or from two or more species in one fish family.
Most species occurred in the intestine, except for Acetodextra amiuri (swim bladder), and
Phyllodistomum staffordi and Phyllodistomum superbum (urinary bladder). At least four species
of larval trematodes (metacercariae) have been reported from eight fish species. The entries
involving Diplostomum spp. are separated based on infection site. It is not known if these are
distinct species of Diplostomum.
Monogeneans
Only two species of monogeneans (Urocleidus adspectus and an unidentified species in the
family Octocotylidae) have been reported from two species of fishes, Perca flavescens and
Coregonus hoyi.
Cestodes
Eight species of adult cestodes representing six genera in five families have been found.
Glaridacris catostomi was found only in catostomids, Eubothrium crassum was found in
Salvelinus namaycush and Lota lota, Bothriocephalus cuspidatus was reported only in Perca
flavescens, Corallobothrium sp. was found in Ameiurus nebulosus, Proteocephalus exiguus was
found in coregonids and Petromyzon marinus, and Proteocephalus pearsei was reported only in
P. flavescens. Eubothrium salvelini infected six fish species in the Salmonidae. Cyathocephalus
truncatus occurred in six species in four fish families. Two species (E. salvelini, C. truncatus)
found as adults also occurred as immature individuals in the intestine of fish. Although
Proteocephalus ambloplitis, Triaenophorus nodulosus, and Triaenophorus crassus occurred as
larval and/or immature stages, adults of these species have not yet been reported from fish. At
least eight species of immature cestodes in five cestode families have been reported. The family
Diphyllobothriidae is represented by three genera (Diphyllobothrium, Ligula, Schistocephalus).
Diphyllobothrium sp. infected five fish species.
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