In zoology there are a number of "-ivorous" terms, designating what
organisms eat (that is, what they primarily subsist on), including:
 
carnivorous - subsisting on flesh or meat (animal prey)
herbivorous or phytivorous - subsisting on vegetable or plant matter
omnivorous - subsisting on a variety of foods (usually animal and
vegetable)
piscivorous - subsisting on fish
molluscivorous - subsisting on mollusks
vermivorous - subsisting on worms
fucivorous - subsisting on seaweeds
fungivorous - subsisting on fungi
insectivorous - subsisting on insects
baccivorous - subsisting on berries
granivorous - subsisting on grain or seeds
frugivorous - subsisting on fruit
graminivorous -  subsisting on grasses
 
The last few terms have more application to ornithology than
malacology, but the terms in the upper part of the list are used in
reference to mollusks.
 
Oh - and now that summer is here, lets not forget those hoards of
pesky sanguinivorous mosquitos!  I don't know if that term applies to
mollusks - perhaps the larval stages of some fresh water bivalves
would qualify??  Any opinion from you Uniologists out there?
Vexillum sanguisugum however, is not sanguinivorous, in spite of its
scientific name.  What an awful name to stick on such a pretty shell
- and totally undeserved!  (sanguisugum = blood sucker)
 
Paul M.