The surprisingly bold and beautiful world of sea slugs

Nembrotha Kubaryana

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nembrotha kubaryana photo
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You'll recognize this nudibranch by its distinctive black, green, and orange coloring; look for them in Indonesia, Malaysia, the Philippines, and Australia.

While nudibranchs are in danger from the same threats that face other marine life -- like pollution and coastal development --their population status is harder to figure out: scientists don't have a good idea of how many exist, total, so it's tricky to determine their decline.

Photo via Prilfish @ flickr