抄録
Eggs of Bothriocephalus opsariichthydis YAMAGUTI, 1934 were collected by dipping its gravid proglottides into sterilized water. The eggs were ovoid and measured 42-57×33-40μ. They had thick, slightly adhesive shells of about 1μ thick and contained no oncospheres when expelled from uterus. The coracidia were hatched out mostly between 2 to 5 days at 25deg;C, but not at 37deg;C and 15deg;C. Light was not needed for hatching. The coracidia were spherical and had cilia of 12-20μ long on the surface. They measured 18-24×15-23μjust after hatching and were enlarged to 76×73μto 107×96μafter 6 hours.
Since the embryos die rapidly at 2-7deg;C, it is assumed that the eggs are unable to survive the winter in the pond.
