When the Octonauts, a team of eight animals who explore the ocean, discover a bleached and abandoned coral reef, they learn about the important relationships among animals, plants, and their habitats.

The Octonauts meet Dunkie, a goldfish who can t stop growing. Finding an ocean big enough for him seems to be an impossible mission for the intrepid crew until they discover a prehistoric, deep sea world. Is Dunkie really a goldfish after all?

Saltwater crocodile: A giant saltwater crocodile wanders into freezing waters so the Octonauts try to return the predator to its warm water home -- Decorator crab: When important objects go missing from their ship, the Octonauts stake out the thief who turns out to be a decorator crab, stealing their things to decorate his shell -- Giant spider crab: Kwazii is frightened when he spots a giant underwater spider, but it turns out to be a very old spider...