Can tegumental morphology be used as a taxonomic criterion between Schistosoma haematobium, S. intercalatum, and S. bovis?

A comparative study of the evolution in time of the tegumental morphology of male adult Schistosoma haematobium from Niger, S. intercalatum from Cameroon and Zaire, and S. bovis from Spain and Sudan was carried out with scanning electron microscopy. Interindividual, interstrain, and interspecies variations are pointed out. The value of the morphological criterion (tegument with or without spines) is discussed. The tegumental morphology can be used for the identification of schistosome species showing strong phyletic affinities under precise experimental conditions. In the present work, this criterion permits the characterization of strains of S. bovis from Sudan and Spain.