>Whelks are Carnivorous and Conchs are Herbivorous. That is the main
>morphological difference. Whelks as well as members of Fasciolariadae are
>voracious carnivores. Conchs (members of Strombidae) are grazers. (I am
>thinking of Strombus gigas, pugilus, alatus, and other shallow/ medium depth
>strombidae)  I'll bet the kid was thinking of the quintessential shell
>Strombus gigas. and the common Busycon Carica.  I hope this helps.
>
 
That definition is fine if you live in the eastern USA. However, in the
Bahamas and West Indies (and Belize) a "whelk" is Cittarium pica, an
herbivore. In the northeast US and British Isles a "whelk" is Buccinum
undatum, a buccinid, and in the southern US it's any Busycon, in the family
Melongenidae, which are carnivores.
 
Conchs, called "Conchas" in Spanish, can be most anything, including
Muricidae, in Mexico and Central America. Even Cassis (which we call Helmet
shells) are known as Conchs in the Bahamas.
 
The answer to the difference is "depends on where you live". Common names
are only helpful in local situations. We need to use Latin to be sure other
shellers know what we're talking about!
 
Peggy Williams
 
                     http://www.mindspring.com/~shellelegant
                                  Peggy Williams
                                   Shell Elegant Tours
                 PO Box 575     *     Tallevast FL 34270
          (941) 355-2291  *   [log in to unmask]