Since the days of the Persian Empire, caviar has trumpeted status, wealth, prestige, and sex appeal. Today it sells for up to one hundred dollars an ounce, and aficionados will go to extraordinary lengths to get their fill of it. According to Richard Adams Carey, that's just the problem. In this journey to caviar's source, Carey immerses himself in the world of sturgeon, the fish that lays these golden eggs. Ancient, shrouded in mystery, inexplicable in several of its behaviors, the sturgeon has a fascinating biologic past - and a very uncertain future. Sturgeon populations worldwide have declined seventy percent in the last twenty years, most drastically in the Caspian Sea. Meanwhile the beluga sturgeon, producer of the most coveted caviar, has climbed to number four on the World Wildlife Fund's most-endangered species list. Carey takes us on a journey across the globe to uncover the secrets of the sturgeon - and meet the real-life characters both profiting from its scarcity and fighting to save it. A high-stakes cocktail of business, crime, diplomacy, technology and the dilemmas of conservation, The Philosopher Fish is the story of a 250-million-year-old fish struggling to survive.