Just to keep everybody scratching their heads..
 
I mentioned Cypraea tessellata a while back. These animals are
basically photophobic. They venture out on the darkest nights
only.
 
And small wonder (or maybe not, if the behavior is inherited).
I can spot one on the walls of a 'pocket' from 30 feet away. Their
mantles are transparent and only serve (if that is the word) to dull
the shine on their shells when they are extended.
 
Then take the Tiger. They are often found in the open with their
mantles down. The big ones are only in danger from shell collectors.
There are fish big enough to get them into their mouths but 1.) these
stay in DEEP water in the daytime and 2.) it is probably a waste of
stomach space to take in something that will not digest easily. I don't
know of any 'crusher' types of fish that can take on these big things.
(And I don't want to run into one if they do exist.)
 
In Hawaii, only a few cowries are found 'in the open.' Tigers, Hump-
back, Netted (tigris, mauritiana, maculifera) are also the largest
(leviathans stay hidden). Everybody else stays inaccessible, if they
can.
 
For species that are active at night, mantle color and pattern, or
color and pattern, are non-items. As was mentioned eariler, the
animal's ecological milieu should be understood before letting
conjecture run rampant.
 
Aloha,
 
makuabob (a.k.a. Bob Dayle)