Studies on the liver fluke Fasciola in Egypt: I--Morphological and morphometrical studies.

A comparative scanning electron microscopy and morphometrical study of the two geographically isolated species of Fasciola (F. heptica European isolate and F. gigantica from Egypt) were studied in order to clarify their genetic relationships and specific identification. Although the present study has revealed that most of the diagnostic morphological and morphometrical criteria in the two species are highly variable, the position of the ventral sucker relative to the whole body length produced the most significant differentiating criterion, in addition to the presence of markedly larger tegumental papillae on the ventral surface of F. gigiantica.