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


----------------------------------------------------------------------

----------------------------------------------------------------------
[log in to unmask] - a forum for informal discussions on molluscs
To leave this list, click on the following web link:
http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1
Type your email address and name in the appropriate box and
click leave the list.
----------------------------------------------------------------------