Quetotaxia cercariana de dos cepas venezolanas / Cercarial chaetotaxy of 2 Venezuelan strains of schistosoma mansoni

RESUMEN

By means of the silver impregnation of two lots of Schistosoma mansoni cercariae belonging to the strains JR (32 cercariae) and C5 (45 cercariac), the number and pattem of disposition of the argentophillic papillae were detertnined with the following results: -Average number of total dorsal papillae 12.1 (JR strain) and 12.0 (C5 strain); the variation coefficients in this surface were less than 4 por ciento (JR strain) and bigger in JR than C5 strain. -Average number of total ventral papillac 12.15 (JR), 11.97 (C5); maximum value of the variation coeficiente 6.4 por ciento (JR), higher in JR than C5 strain. -When the ventral surface was classified in four quadrants, the average number of papillae by quadrant was quadrant A 1. 15 (JR) and 1.06 (C5); B 1.06 (JR) and 1 (C5); C 4.97 (JR) and 4.96 (C5); D 5.03 (JR) and 4.98 (C5). The variation coefficients were higher in the A and B ventral quadrants, reaching maximum values of 31.9 por ciento, and 61.0 por ciento for the posterior quadrants C and D. -When the ventral surface was divided in three equal parts for determining the position of the most variable papillae of this area, the greatest value of the variation coefficients obtained were for the 2nd thirds of the cercariae 89.8 por ciento and 76.8 por ciento for C5 strain and 43.5 por ciento and 56.8 por ciento for JR strain. In relation to the total lateral papillac, the average numbers were 17.0 (JR) and 16.6 (C5), with a maximum value of variation coefficient of (8. 1 por ciento (C5). The average total numbers of papillae of the tail were 25.6 (JR) and 26.1 (C5) for the ventral surface and 20.72 (JR) and 21.33 (C5) for the dorsal papillae. The comparison between the percents of the cercariae of two S. mansoni strains with more than 1 papillae on the anterior ventral quadrants A or B (94 por ciento JR and 34 percent C5), resulted with significant diferentes (P < 0.05) (AU)##