>    Is Marisa c. there in any great numbers? And how do they "escape"
>into any headwaters? Are the larva carried in fish gills as are many
>species of mollusks in Kentucky waters?
>     Art

By "escaped" you should read "was introduced to" by someone dumping
aquarium contents...

Only bivalves of the Unionoidea are parasitic on fish gills. Marisa,
an operculate gastropod, I believ hatches as a "nymph" from its eggs
and crawls away (someone please correct me if I'm wrong!).

In a Fort Myers river I saw large numbers of large Marisa, and
clooected quite a few. Really nice shells...
--
Andrew Grebneff
Dunedin, New Zealand
64 (3) 473-8863
<[log in to unmask]>
Fossil preparator
Seashell, Macintosh & VW/Toyota van nut
________________________________
I want your sinistral gastropods!
________________________________
Opinions in this e-mail are my own, not those of my institution
_______________________________________________
A: Because it reverses the logical flow of conversation.
Q: Why is top posting frowned upon?