Chemical communication in hermaphroditic digenetic trematodes.

Adult hermaphroditic digenetic trematodes show a tendency to pair or aggregate in vivo, on the chick chorioallantois, and in vitro. Intraspecific pairing studies onEchinostoma revolutum, Leucochloridiomorpha constantiae, andAmblosoma suwaense are reviewed. Lipophilic excretory-secretory products are involved in chemical communication in hermaphroditic digeneans. Free sterols are involved in chemical attraction inL. constantiae andE. revolutum and sterol esters play a similar role inA. suwaense. In vitro pairing betweenE. revolutum and various other digenean species suggest that interspecific pairing occurs in Digenea and that nonspecific factors are involved.