Does anyone out there know of any recent work (last 10-20 years) describing
the methods that various cercariae use to get out of the snail
intermediate host? The only references I could find are the 3 cited by
Wright in "Flukes and Snails" (1971) dating 30+ years ago describing
migrations within the different sinuses until penetrating through the
mantle. This makes sense for the motile cercariae even though the actual
mechanism of penetration was not given. Schmidt and Roberts list a
reference to escape glands in schistosome cercariae but also say that
"their function is unknown." Do other cercariae have similar glands?
Also, what about non-motile cercariae (at least when outside of the
snail)? It is hard for me to imagine them maneuvering about inside the
snail and then penetrating the skin.
I understand that many rediae have birth pores, but that
some do not. How do the cercariae even get out of the rediae then?
I realize that I packed a lot of questions in this post, but I would be
grateful for any bits of information regarding any of them.
Brian Keas -> keasbe9 at wfu.edu
**Disclaimer: This product is sold by weight, not by volume. Some settling
of contents including typos, errors in logic, and just plain stupidity
may have occurred during shipping.**