About this programme

8/10. David Attenborough turns his attention to marine invertebrates - bizarre and beautiful animals that thrive in the toughest parts of the ocean. Divers swim into a shoal of predatory Humboldt squid emerging from the depths to hunt in packs, and timelapse photography reveals starfish gathering under the Arctic ice to devour a seal carcass. A camera also follows a female octopus into a cave, where she hides to protect her eggs until she starves to death.