Today we’re celebrating the world"s largest fish, the whale shark. These gentle giants can grow up to 40 feet long, with one reaching a record 61.7 feet. Found in tropical oceans, these filter feeders glide through the water, mouths wide open, straining plankton and small fish. The patterns on their dotted, starry skin are as unique as a human fingerprint. Sadly, the International Union for Conservation of Nature lists whale sharks as endangered due to overfishing, habitat loss, and climate change.