Kay Peterson wrote:
>
> What is the purpose of the bored holes?  Are they for the purpose of
> injecting some anesthetic or poison?  I always wondered why some
> bivalves had large holes near the beaks--which would seem to be the
> thickest part of the shell.  The gastropods seem always to have the
> holes bored on the underside, at the juncture of the body whorl and
> the spire.
> Thank you.
>
> Kay Peterson

A large part of my collection came from O. vulgaris middens, some from
O. briareus. Generally, the univalves are drilled and the bivalves are
not. The octopus usually drills the gastropods first and then eats the
occupant. Bivalves are frequently saved for later meals, and are opened
with brute force.