>Cypraeidae (true cowries) and Columbellidae (dove shells) are two families
>that come to mind that contain both carnivores and herbivores. Actually,
>it's hard to classify some mollusks as one or the other. Some grazers are
>omnivores, taking in sessile animals along with algae. If you eat eel grass
>or turtle grass, you'll get bryzoans and hydroids too. If you slurp up mud,
>you might get nematodes and foramiferans.
>
>---------------------------------------------------------------------
>Gary Rosenberg, Ph.D.                     [log in to unmask]
>Malacology & Invertebrate Paleontology    gopher://erato.acnatsci.org
>Academy of Natural Sciences               http://www.acnatsci.org
>1900 Benjamin Franklin Parkway            Phone 215-299-1033
>Philadelphia, PA 19103-1195 USA           Fax   215-299-1170
 
Hi All,
 
I have contributed to discussion occasionally in the past and am very
interested in this topic.  I am a graduate student at UC Santa Cruz and am
working on the feeding preferences of the cowrie Cypraea spadicea. This
cowrie appears to be an omnivore and eats ascidians, sponges, etc as well
as kelp.  In response to Gary Rosenberg's comment, while cowries in the lab
willingly eat kelp,  when given a choice between kelp vs kelp encrusted
with bryozoan (Membranipora), they go after the bryozoan with gusto and
completely ignore the kelp (like scraping off the icing on a cake).  These
choice tests are conducted in Plexiglas chambers (constructed somewhat like
a y-tube with unidirectional sea water flow).  Almost all cowries tested
moved into the side with the bryozoan/kelp as opposed to the kelp only
side.  Pretty amazing cows!
 
Regards,
 
Susie