Abstract
Enzyme phenotypes of 3-hydroxybutyrate dehydrogenase, phosphoglucose isomerase, isocitrate dehydrogenase, alpha-glycerophosphate dehydrogenase, glutamate-oxaloacetate transaminase, mannose-6-phosphate isomerase, phosphoglucomutase and esterase in six populations of Biomphalaria from the Americas are given. The species studied are B. glabrata, B. straminea and B. tenagophila. It is suggested that enzyme electrophoresis presents a valuable extension of characters for a better identification of the American species of Biomphalaria.