Somatic chromosomes of Schistosoma rodhaini, S. mattheei, and S. intercalatum

Karyotypes are reported for three African schistosomes: Schistosoma rodhaini, S. intercalatum, and S. mattheei. All have eight pairs (2n = 16) of chromosomes which comprise three distinct size groups: A, large (two pairs); B, medium (three pairs); and C, small (three pairs). Chromosomes of groups A and B are subtelocentric; those of C are more metacentric or submetacentric. These karyotypes prepared with conventional Giemsa staining are very similar to each other and to those of S. mansoni and S. haematobium. As a group, the African schistosomes studied to date exhibit clear differences in chromosome morphology from the Asian S. japonicum and S. mekongi.