Scanning electron microscope observations on adult Schistosoma japonicum.

The integumental surfaces of critical point dried adult Schistosoma japonicum were studied by scanning electron microscopy. There are no bosses or spines on the dorsal surface of the male, which is ridged and presents a spongy appearance. Many spines cover the inner surface of the oral sucker and extend to the pharyngeal opening. The oral sucker shows a rim with spines of variable size and sharpness inward and outward from the rim. The ventral sucker possesses many spines which are smaller than in the oral sucker. The lining of the gynecophoric canal is roughened by minute spines. The integument of the female is ridged and pitted and possesses fewer spines than in the oral sucker, the ventral sucker, and the gynecophoric canal of the male. Anterior to the acetabulum, the integumental surfaces are devoid of spines. However, in the other areas, spines are equally distributed except for the vicinity of the excretory pore.