Re: Apple Snails/Mystery Snails

>From: crom at cris_com (Crom)
>Date: Wed, 15 Jan 1997 22:18:11 GMT
>The mystery snails sold in shops here in SW OH (the midwest US) aren't
>livebearing.  They lay their eggs up above the water line, and look
>identical to apple snails, only smaller -- the largest one I have is
>about the size of a golf ball.  In my experience, they only bother the
>plants (with the exception of Hygrophila) if there aren't enough
>leftovers.  This happened to me when my first egg mass hatched in a 20
>gallon planted tank.  The 150 or so miniscule mysteries set about
>devouring everything in sight.=20
>I've read, as well, that there are livebearing mystery snails.  I've
>also read that mystery snails are apple snails, only smaller.  Perhaps
>this is true, since mine, if given adequate food, will grow at a
>prodigious rate.

I'm basing my information off of the TFH book, which also contains some
information that my experience disagrees with (when it says that all
Pomacea snails are voraceous plant eaters and that egg clutch yeilds are
always low).

In this source, I believe they say the mystery snails are the livebearing
variety and apple snails are a specific Pomacea species from South America
from which the yellow, pearl, gray, and normal brown-striped apple snails
we see in stores come from.  I don't have the documentation in front of me,
but they indicate that a tremendous amount of confusion and misapplied
naming has occurred over the last 75 years, so I'm just taking their
identification and using it for lack of a better system.

>An odd thing with my first "mystery" snail eggs.  Don't they change
>sexes (bisexual?)?  I bought one mystery snail, and about 3 months
>later, having no contact with any other snails, it laid EGGS.  Not
>just eggs -- EGGS, about 5 masses.  I let ONE mass hatch, and got
>between 150 and 200 snails.  Can this snail store sperm (or the snail
>equivalent thereof), its own or another snail's, and use it to
>fertilize itself when conditions are right?  How can I stimulate them
>to breed?  Abundant food supply?  David, you said feeding them
>powdered lime?

This is interesting.  I would conclude that either the eggs develop inside
the female's shell before they are laid, or that she can store sperm for
some period of time.  Once again, I'm relying on TFH for information, but
they indicate that Apple snails have definite sexes.  I would tend to agree
with this observation since I have three large, well-fed apple snails in my
20g tank which have never laid eggs.

I've been feeding them Hikari algae wafers, and adding powdered limestone
to the water occasionally as well.  I noted the first time I added powdered
limestone that the snails all gathered to the area where the limestone
primarily settled, and I could see them eating it directly off of the sand
in the bottom of the tank.  I suspect they were extremely calcium deficient
the first time, but they still gather when I add limestone.

>BTW, how large do those brown-spotted ramshorns get?  Can't say I've
>ever seen any.

I suspect they're lumped in as red ramshorns by most aquarists.  I make a
distinction.  The red ramshorns lay their shells over on the side while
they're babies and tend to carry them that way as adults too.  Their
babies' shells are somewhat pink and very narrow in cross-section as well.
The brown spotted ramshorns are about the same size (5/8" adults) but have
much wider, upright, brown shells as babies, and they develop faint spots
in the shells as juveniles.  I find that both species look pretty much the
same as adults.

David W. Webb           Corporate Business Systems
Texas Instruments Inc.  Dallas, TX USA
(972) 575-3443 (voice)  MSGID:       DAWB
(972) 575-4853 (fax)    Internet:    dwebb at ti_com
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