Fighting Conch Shell - Former Aquarium Tank Denizen

Description

Ten years ago, this fighting conch was an inhabitant of my marine fish and invertebrate tank.  It attached itself to the front glass with its large bright orange foot and each time I removed it, it returned to the same place, so I left it alone.  It survived for a few years, and after its demise, I placed it in a sunny spot outside and left it there all summer.  After a few months, it stopped smelling and it was thoroughly cleaned, so now all that remains is the shell, with no trace of the original animal.
It measures 7.5" in length and 3" in width.  It also is fluorescent, glowing a pinkish orange under both long and shortwave ultraviolet light (brighter under long wave - see photo 5).  Any black light will demonstrate this.