The common name of Marisa cornuarietis is Giant rams-horn while that of
Planorbella trivolvis is Marsh rams-horn.
Henk

----- Original Message -----
From: "G Thomas Watters" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, February 13, 2004 6:51 PM
Subject: Re: Ramshorn


> In Ohio (where Art resides), the aquarium Ramshorn is usually either
> Planorbella trivolvis (Say, 1817) (which, while native to the area,
> probably came from somewhere else) or the exotic Marisa cornuarietis
> (Linneaus, 1758). Trivolvis is a smallish, brown snail (maybe to 3/4 inch)
> whereas Marisa is large (1.5-2 inches), usually boldly striped. Marisa is
> actually an atypical ampullariid. Trivolvis usually ends up in your
> aquarium from purchasing aquatic plants - most shops don't sell trivolvis.
> Marisa is usually sold as an aquarium specimen. Albino Marisa are popular
> and are golden in color. Marisa is from Central and South America.
>
> G. Thomas Watters, PhD