Critter of the Week: pupu tarakihi or knobbled argonaut

This week's critter creates one of the most beautiful shells in the ocean. But they're not your run-of-the-mill shell-dweller: the pupu tarakihi or knobbled argonaut (Argonautus nodosus) is one of the world's weirdest octopuses. Female knobbled argonauts create their beautiful translucent shells by excreting minerals out of two enlarged tentacles. They are the only creature in the world that makes a shell out of their own arms. The shells are both a nursery for their eggs and young and a place to tuck away as they drift on the ocean surface.