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The effect of posthodiplostomosis on the cyprinid fish fry
Ondračková, Markéta ; Dyková, Iva ; Gelnar, M. ; Jurajda, Pavel
Posthodiplostomosis, called also black-spot disease, is caused by metacercariae of Posthodiplostomum cuticola (Trematoda, Diplostomatidae). These parasites were studied on the cyprinid fish in floodplain area of the River Dyje in South Moravia. Twelve species from 16 totally explored Cyprinids were infected by metacercariae of P. cuticola during 1998, 1999 and 2001. Roach (Rutilus rutilus), rudd (S. erythrophthalmus), silver bream (B. bjoerkna), common bream (A. brama), bitterling (R. sericeus) and Prussian carp (C. auratus gibelio) were infected in all followed seasons. These species were histologicaly examined. During the cyst development the progressive maturation of connective tissue in outer layer of the cyst and infiltration of pigment cells were observed. Production of black pigment around the parasite cyst was chacteristic host reaction. Mainly melanocytes and in a small measure iridocytes took part in the pigmentation. The metacercariae of P. cuticola caused in the juvenile fish spine and body deformation. By high invasion the tissue dystrophy was observed.
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Monogenean parasites of fishes of economic importance
Gelnar, M. ; Blažek, R. ; Matějusová, I. ; Ondračková, Markéta ; Šimková, A.
To date , altogether 165 species of monogenean parasites have been recorded on the territory of Czech and Slovak Republics. In comparison with the status of monogenean organismal diversity described in monograph published by Ergens and Lom (1970): "Causative Agents of Fish Diseases", there is a significant increase in regional parasite species richness. During last 30 years, 47 species of monogeneans have been newly recorded in the mentioned territory. Following three reasons trying to explain the situation: 20 monogenean species have been recognized like species nova for science after 1970; another 14 parasite species have represented a new zoogeographical records in central Europe and finally altogether 11 monogenean species have been introduced to our fauna from exotic regions.
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