The Urchin Invasion
Season 3, Episode 1
Octonauts and the Urchin Invasion Season 3 Episode 18 New Episode.mp4 000589800
Air date May 02, 2014
Episode guide
The Great Arctic Adventure
The Lion's Mane Jellyfish
 Kelp-eating red sea urchins attacking a kelp forest.  The Octonauts are helped by Shellingtons's sister, Pearl, another sea otter and scientist. 

Creature Report

Red Urchin

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