Hi Tom
Many thanks for your quick and informative reply. I have plenty of practical
experience with these cute little critters, but keep coming up against a
brick wall when I try to find anything else out about them. Some suppliers
to the aquarium trade claim to captive-breed these snails, but they
steadfastly refuse to give any details. I have long suspected that even the
species names they provide us with are not correct. All I have been able to
do is extrapolate from scientific papers in my university's library about
related species, which is how I guessed that they probably produce veligers
which grow up in the ocean. But because T. fluviatilis is a nerite and
doesn't do this, I didn't feel able to be sure (because T. fluviatilis is
native here in England, I do have access to accurate info about this
species, at least).
Your email has answered many of my questions at one stroke! I'd very much
appreciate you forwarding me any pics you might have. My email is:
[log in to unmask]
Assuming you're right about the species I have, do you know where in the
world they come from? I guessed Indo-Pacific?
Kind regards,
Anna
----- Original Message -----
From: "Tom Eichhorst" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, May 12, 2007 3:06 PM
Subject: Re: Help With Neritidae
> Anna,
>
> The information you seek is indeed tough to find, which is why I started
> writing a book on nerites about 6 years ago. If you will send me your
email
> address I will forward images of the species you named so you can compare
> them to the shells in your aquarium. At a guess based on occurrence and
> availability, I would think you have: Vittina coromandeliana (much more
> common than your Neritina [sic] turrita), Clithon corona (Clithon
brevispina
> is a synonym), and Septaria porcellana the most common of this genus). As
> for reproduction, most fresh or brackish water nerites (all those you
named)
> are amphidromous, that is they lay egg cases full of eggs that hatch into
> veligers that wash out to sea. Once in salt water they mature to small
> snails that much crawl back to fresh or brackish water to live. So your
> critters (who reproduce sexually) will lay eggs throughout the tank, but
the
> hatchling veligers will survive only a short while. A filter system would
> trap most of them in any case. A notable exception to this mode of
> reproduction is Theodoxus fluviatilis, the common punt snail found
> throughout Europe and much of England. It lays a typical egg case, but
the
> case contains only a single or very few fertile eggs. These hatch and
feed
> off the infertile eggs until they can leave the egg case as miniature
> adults. Regards,
>
> Tom Eichhorst
>
> -----Original Message-----
> From: Conchologists List [mailto:[log in to unmask]]On Behalf Of
> Anna Robinson
> Sent: Saturday, May 12, 2007 6:42 AM
> To: [log in to unmask]
> Subject: Help With Neritidae
>
>
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