Echinostoma trivolvis: mating behavior of adults raised in hamsters.

Echinostoma trivolvis adults grown in golden hamsters were treated in vitro with [3H]-tyrosine to label sperm and transplanted to uninfected hamsters alone or with four to six unlabeled adults. After 4-5 days, worms were recovered, processed for autoradiography, and observed for silver grains over their seminal receptacles. Of 11 worms transplanted singly, 6 (55%) self-inseminated. In multiple-worm situations, 7 of 12 (58%) labeled worms self-inseminated, and in the process the 12 labeled worms inseminated only 5 of 35 (14%) possible unlabeled worms. E. trivolvis adults self-inseminated when isolated and both self- and cross-inseminated in groups, suggesting an unrestricted mating pattern. These results were compared with the mating patterns of other digenetic trematodes.