Andy:
As omnivorous as crayfishes are, it is no surprise that there are numerous
references in the literature to their consumption of snails (including the
'ramshorn' genera listed by Henk in this thread, such as Helisoma).
Citations of their molluscan prey items can be found in Trophic
Relationships of North American Freshwater Crayfishes and Shrimps by HH
Hobbs III, a 1993 Milwaukee Public Museum publication.
Copies may be obtained through me.
Joan Jass
Curator of Non-insect Invertebrates
Milwaukee Public Museum
Email [log in to unmask]
Phone 414-278-2761
-----Original Message-----
From: Andy Rindsberg [mailto:[log in to unmask]]
Sent: Friday, February 13, 2004 10:29 AM
To: [log in to unmask]
Subject: Re: Ramshorn
Art and Henk,
I've seen 'ramshorn' shells used very strikingly in necklaces. What is known
of the ecology of snails having this shape? The planispiral form is unusual
today, but was common in marine mollusks during the early Paleozoic. Geerat
Vermeij thinks that having an umbilicus (hollow) on both sides of the shell
leaves a planispiral mollusk open to attack by arthropods having large
pincers: crabs, for instance. Of course, crayfish are common in many
freshwater environments, and they have pincers. Do crayfish eat ramshorn
snails?
Andy
Andrew K. Rindsberg
Geological Survey of Alabama
-----Original Message-----
From: Conchologists of America List [mailto:[log in to unmask]] On
Behalf Of mienis
Sent: Friday, February 13, 2004 10:20 AM
To: [log in to unmask]
Subject: Re: Ramshorn
Art, shalom!
Finely some sense from "zoomtown".
The epiteth "Ramshorn" says nothing except for the fact that it belongs to
the Planorbidae. As a matter of fact according to Turgeon et al., 1998.
Common and Scientific names of Aquatic Invertebrates from the United States
and Canada: Mollusks. 2nd Edition. American Fisheries Society Special
Publication, 26: 526 pp., there are at least 27 or 28 Ramshorn species
living in North America. They belong to the following genera: Biomphalaria
(1); Drepanotrema (3); Helisoma (2); Planorbella (19); Planorbula (1) and
Vorticifex (1 or 2). A world wide Ramshorn species in freshwater aquaria is
Planorbella duryi (Wetherby, 1879) or Seminole rams-horn. I hope that this
is of some help. And by the way: stick to the molluscs. There are so many
interesting subjects concerning those creatures. Best regards, Henk K.
Mienis
[log in to unmask]
----- Original Message -----
From: <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, February 13, 2004 5:52 PM
Subject: Ramshorn
> Dear anyone;-
> I recently added a "Ramshorn" Snail to my freshwater aquarium. Can
someone tell me the proper name for the beast?
> Art
>
> PLEASE NOTE: My new, long-term, and correct email address is:
[log in to unmask] Please update your records!
>
>
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