Life under the sea can seem so odd to us terrestrial animals. But for creatures like this black margined nudibranch (Doriprismatica atromarginata), with its petticoat frills and graphic elegance – not to mention the apparition of an expressive little face – it's just business as usual. Thank you to photographer John Turnbull who often treats us to the fantastic oddities that the ocean has to offer.
Would you like to see your nature photo featured as the TreeHugger photo of the day? Join TreeHugger’s Reader Photo Pool on flickr and add your pictures to the group.