Sixteen strains of trypanosomes isolated from the blood of 10 freshwater fish species (all but one from South Bohemia) were characterized by enzyme analysis using dise electrophoresis in 5% polyacrylamide gel. Six enzymes were selected: ADH, LDH, MDH, ME, G6PDH and GPI. The most variable were ADH and LDH, whereas MDH, G6PDH and GPI showed the same pattern in all strains analysed. Cluster analysis indicated a very high degree of similarity among strains, even those isolated from phylogenetically distant hosts. Moreover, no correlation between enzyme pattern and host species was found.
