[Taxonomic analysis of Pegosomum asperum and P. saginatum (Trematoda: Echinostomatidae)].

Morphology, ecology and chromosomes of P. asperum and P. saginatum were investigated. The both species have a diploid set consisting-of 20 chromosomes with similar morphology and size of bivalents. Their karyotypes are supposed to be identical. According to their morphology and ecology the both species are clearly differentiated. A conclusion is drawn on the distinct status of these trematodes having originated as a result of simpatric speciation.