The number and pattern of argentophilic papillae (chaetotaxy) of Schistosoma mansoni cercariae, permits the differentiation between the male and the female of this larval stage, through the following criteria: - A greater homogenity in the male cercariae concerning the number of ventral and dorsal papillae on the body and tail (C.V.= 4.1%), than in the female cercariae (C.V.=18.3%) (p<0.001). - The presence in the 80% of the male cercariae of papillae on the inferior-right and left quadrant, respectively, on the ventral surface; while this criterion is only present in the 40% of the female cercariae (P<0.001). A significative statistical difference (P<0.001) between the average number of ventral body papillae in the female cercariae (X =11.9 ± 0.2) and the male cercariae (X = 11.1 ± 0.3). -A significative statistical difference (p<0.05) for the average of the major distance between the papillae AIL-AIIL for each cercariae in relation to the sex (men = 25.5 µm, women = 27.3 µm).
Schistosoma mansoni; cercarial chaetotaxy; sex identification