Two sibling species of Biomphalaria, B. tenagophila and B.
occidentalis were identified using isozyme patterns obtained by
horizontal gel electrophoresis. Six diagnostic enzymatic loci
were identified in digestive gland homogenates. The results
enable us to distinguish the species, calculate the Nei's
coefficient of genetic similarity, atwl provide a basis for
making inferences about the pattern of these two plonorbid
species colonization and distribution.
