Two strains of Schistosoma mansoni (Belo Horizonte, MG and S. José dos Campos, SP, Brazil) are morphologically studied. Some numerical characteristics are found to be different between the strains. These differences are as follows: lenght, distance from the oral sucker until the ventral sucker, distance between the anterior pole of the worm and the distal part of the gonads and finally the number of testes.
Schistosoma mansoni; Schistosomiasis