Actually, according to the Harding/Mann report in the Journal of Shellfisheries Research, June 1999: "Chesapeake Bay R. venosa readily open and consume large hard clams (30-85mm SH) leaving no visible signs of either drilling or boring behavior. R. venosa grasps its prey along the shell margin and covers the clam with its foot until the clam gapes slightly. When the clam gapes, the Rapana inserts its proboscis between the clam valves and begins feeding. The entire clam is consumed leaving clean, empty articulated valves with no visible predation signature as the end product." (Harding and Mann, 14)  The paper does acknowledge the previous reports of Gomoiu 1972 and Carriker 1981 of Rapana venosa actually being a drilling/boring snail and Chukhchin's 1984 report of the use of Paralytic toxins during feeding. The citation for this paper is

Harding, J. & R. Mann. 1999.  Observations on the Biology of the Veined Rapa Whelk, Rapana venosa  Valenciennes, 1846) in the Chesapeake Bay, J. Shellfish Res. 8: 9-17.

Sarah


*~*~*~*~*~*~*~*~*~*~*~*~*~*~
Sarah R. Watson
Curatorial Assistant
Dept. of Malacology
Academy of Natural Sciences
*~*~*~*~*~*~*~*~*~*~*~*~*~*~
http://www.geocities.com/scalaria

>>> [log in to unmask] 11/09/00 12:59PM >>>
Strombus grazes on algae. Rapana bores into live bivalves, though it probably would accept other prey if it can catch it.  Busycon is also a predator/scavenger.  It preys on bivalves by wedging them open with the outer rim of the aperture.  I had one in a tank that broke a Mercenaria shell in this manner rather loudly.

    Dr. David Campbell
    "Old Seashells"
    Biology Department
    Saint Mary's College of Maryland
    18952 E. Fisher Road
    St. Mary's City, MD  20686-3001 USA
    [log in to unmask], 301 862-0372 Fax: 301 862-0996
"Mollusks murmured 'Morning!'.  And salmon chanted 'Evening!'."-Frank Muir, Oh My Word!