This beautiful creature is a creature of the high seas, floating just under the surface of the world’s oceans. We often find it on the beaches of New South Wales washed up amongst other species in a “Blue Tide”line.
Remarkably this swimming nudibranch eats Bluebottles (the Portuguese man ‘o War jellyfish, Physalia physalis) and ingests their stings whole. This makes it dangerous to handle as it can have up to 50 whole sting cells in its body at any time. Glaucus atlanticus
Thanks for information to Guye Richards and WJ Dakin