As a documentary photo, this is fine, but I generally don't like to have photos of other people's thumbs on my desktop or living room wall (my thumb is a fine subject though!) =)
I tend to agree with the comment above. Perhaps next time you should hold the shell in your teeth :-).
It's a beautifully translucent shell with wonderful colors. Since this is supposed to be a comment about your posting, I'll say that I might have considered a different presentation (other than holding it in your teeth.) I probably would have cropped out the white sky. On a separate matter, QUIT BITING YOUR NAILS" LOL.
Thanks for posting.