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

hyperplasia and mucous cell depletion in the skin. Dechtiar (1972a) reported that substantial
mortality of young Perca flavescens in Lake Erie was due to Ichthyophthirius multifiliis.
Trichodina urinaria can cause inflammation of the ureters and Trichodina sp. can produce
hyperplasia of the gill lamellae. Of the myxozoans, Henneguya spp., Myxobolus spp., and
Thelohanellus notatus are most important, infecting a variety of non-intestinal sites and causing
damage to the gills, muscle, internal organs, and skin (Dogiel et al. 1958; Reichenbach-Klinke
and Elkan 1965; Reichenbach-Klinke 1973). Two of the microsporans (Glugea anomala and G.
cepedianae) cause hypertrophy of cells, and mortalities of Pungitius pungitius have been ascribed
to Glugea anomala (see Sindermann 1970).
Digenetic Trematodes
The following adult digenetic trematodes may be pathogenic to fish: Crepidostomum (5 species
reported), Acetodextra amiuri, Phyllodistomum (8 species reported), Sanguinicola occidentalis,
and Sanguinicola sp. (Davis 1937; Perkins 1951, 1956; Wales 1958b; Gleason et al. 1983). The
larval trematodes (Clinostomum complanatum, Centrovarium lobotes, Crassiphiala bulboglossa,
Diplostomum (4 species reported, including Diplostomum spathaceum), Neascus sp.,
Posthodiplostomum minimum, Uvulifer ambloplitis, Apophallus brevis, Ichthyocotylurus
intermedia, Ichthyocotylurus sp., and Tylodelphys scheuringi are pathogenic to fish affecting the
skin, eyes, brain, internal organs, and muscle (Meyer 1958; Wales 1958b; Kozicka 1958; Sinclair
1972). Bychovskaya-Pavloskaya and Petrushevski (1963) reported on the mortalities of fish
caused by adult and larval digenetic trematodes.
Monogeneans
Some of the ancyrocephalid species, several Dactylogyrus spp., Discocotyle sagittata, several
Gyrodactylus spp., Tetraonchus monenteron, and T. variabilis are monogeneans that, when they
occur in high numbers, can cause pathology and hyperplasia of gill lamellae (Mizelle 1938;
Tripathi 1959; Prost 1963; Lester and Adams 1974). Discocotyle sagittata has caused mortalities
to fish due to damage to the gills (Blood et al. 2006).
Cestodes
Adults of Eubothrium crassum, E. rugosum, E. salvelini, and Cyathocephalus truncatus have
been known to cause pathology to fish (Vik 1954; 1958; Smith and Margolis 1970; Boyce 1979).
The plerocercoids of Diphyllobothrium ditremum, D. laruei, Diphyllobothrium sp., Ligula
intestinalis, Schistocephalus solidus, Proteocephalus ambloplitis, Triaenophorus crassus, and T.
nodulosus that infect the liver, mesentery, and gonads can cause inflammation and other
pathology resulting in major damage (Bangham 1927; Lawler 1969; Matthey 1963; Dechtiar
1972a). Plerocercoids of Proteocephalus ambloplitis can reduce the reproductive capacity of
female Micropterus dolomieu by fibrosis of the ovaries and direct oocyte destruction (Esch and
Huffines 1973; McCormick and Stokes 1982).
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