INTERSPECIFIC RELATIONSHIPS BETWEEN THE TREMATODES CALICOPHORON CALICOPHORUM AND GASTROTHYLAX CRUMENIFER

The research purpose was to investigate the interspecific relationships between the trematodes Calicophoron calicophorum and Gastrothylax crumenifer in naturally infected animals. Helminthological material was collected from cattle in the Central and Northwestern Regions of the Republic. The infection degree was established by helminthological dissections. Out of 100 examined animals, 17 were found to be infected with paramphistomates. A full dissection was performed on 8 animals infected with the trematodes C. calicophorum and G. crumenifer. The remaining animals were mono-infected. The results indicate an antagonistic relationship between the populations of these trematodes: the higher the number of C. calicophorum, the lower the number of G. crumenifer. A high infection degree affects the size of the trematodes — the higher the infection, the smaller the size of the parasites. The body size of the trematodes is not likely influenced by the suppression by the host's antibodies, but rather by spatial or trophic competition and limited resources. The decreased parasite size is seen as a response aimed at reducing energy demands and preventing the host death, as the host death would also lead to the parasite death. The research results found partial antagonism between C. calicophorum and G. crumenifer maritas, which has important scientific and practical significance.