There are no studies specifically relating to predators and defenses in west-coast moon snails. Euspira lewisii crawls about openly on the sand and, in intertidal locations, is sometimes exposed to air or at least is shallow enough to be visible and accessible to birds. The flesh is plump and seemingly tasty to fishes, so if fishes avoid moon snails as prey, the liklihood is that the flesh is toxic or otherwise unpalatable. The shell is strong and protected by a proteinaceous operculum (see photograph on Right), but moon snails are rarely observed to be withdrawn in their shells. Clearly, research on the subject is needed.
Moo
n snail Euspira lewisii, possibly with its own egg collar,
exposed on a sandflat. The snail is attempting to close
its operculum, but some fleshy parts are stuck 0.3X
There are no studies specifically relating to predators and defenses in west-coast moon snails. Euspira lewisii crawls about openly on the sand and, in intertidal locations, is sometimes exposed to air or at least is shallow enough to be visible and 
accessible to birds. The flesh is plump and seemingly tasty to fishes, so if fishes avoid moon snails as prey, the liklihood is that the flesh is toxic or otherwise unpalatable. The shell is strong and protected by a proteinaceous operculum (see photograph on Right), but moon snails are rarely observed to be withdrawn in their shells. Clearly, research on the subject is needed.