Egg viability studies on Clinostomum complanatum (Digenea: Clinostomidae) from two experimental animal model systems.

Viability of eggs is important for the successful completion of trematode life cycle, both in natural and laboratory conditions. The present study was designed to check the viability of eggs released by the digenetic trematode parasite Clinostomum complanatum transformed in experimentally infected chicken and rabbit eye. The incubation of the released eggs in distilled water at 28 ± 1 °C led to the embryonation followed by hatching on tenth day to release miracidia. These can be used to infect the snails. We propose that these two in vivo model systems can be used as a source of viable eggs for further studies on developmental biology and life cycle where in law-protected animals are not to be used. To the best of our knowledge, in contrast to the previous attempts, this is the first successful study to report any experimental model to produce ovigerous adult worms capable of releasing viable eggs.