Neighbour-Joining tree for Bulinus isolates using the 'Folmer' cox1 fragment, transversions only. Neighbour-Joining tree using transversional substitutions only for the cox1 'Folmer' region. Calculation parameters are the same as for Figure 7. This region is proposed for potential use as a barcode. Bootstrap values below 50 are not shown. B. africanus group isolates are shown in red, B. forskalii in green, B. reticulatus in black and B. truncatus/tropicu s in blue. See Table 1 for origins of isolates.