Although Biomphalaria occidentalis and B. tenagophila are
indistinguishable on the basis of shell morphology and the majority of
their genital organs, only the latter is susceptible to infection with
Schistosoma mansoni. Thus, the identification of these species is
fundamental to epidemiological studies of schistosomiasis. Here we describe
a simple and rapid method for differentiating B. tenagophila from
B. occidentalis based on low stringency polymerase chain reaction
and using a pair of primers specific for the amplification of the 18S rRNA
gene. Analysis of the low stringency product profiles of populations of
these snails from different geographical regions confirmed this approach
as being applicable to the identification of B. tenagophila and
B. occidentalis in cases where classical morphology is inconclusive.
