From
Daniel C. Dennett: In the United Kingdom, the law regarding
cruelty to animals draws an important moral line at whether
the animal is a vertebrate: as far as the law is concerned,
you may do what you like to a live worm or fly or shrimp,
but not to a bird or frog or mouse. It's a pretty good place
to draw the line but laws can be amended, and this one was,
Cephalopods, were made honorary vertebrates, in effect
because they, unlike their close mollusk cousins the clams
and oysters, have such strikingly sophisticated nervous
systems.
MJB