Abstract
Opalina sudafricana reacted by encystation to small doses (0.04 ml) of fresh toad bile injected subcutaneously into its host Bufo regularis. It is speculated that androgens present in the injected bile of male toads, and oestrogens found in injected bile of female hosts reach the parasites in the recta of the treated animals and induce them to encyst. High doses of bile killed the parasites and their hosts. Small doses of bile (0·04 ml) added to in vitro cultures induced encystation in the opalinids. High doses killed the opalinids in vitro. There is also the possibility that bufodeoxycholic acid found in the toad bile may play a role in inducing the parasites to divide and encyst.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
