Dear Andrew and Blue:-
    I'm confused. You have mentioned dumping aquarium materials as the reason some species are in local rivers. It occurs to me that when people "dump" primarily water products, they do so down a toilet or a storm drain. The material then goes to a water purification plant which kills everything including bacteria before it is released into local rivers. How do snails survive this?
    Q-Man
>
> From: Andrew Grebneff <[log in to unmask]>
> Date: 2004/02/15 Sun PM 02:46:38 EST
> To: [log in to unmask]
> Subject: Re: Marisa and ramshorns
>
> >    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?
>

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