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What is a nudibranch?

Nudibranchs — also called sea slugs — are a group of over 3000 small mollusks that live in the ocean. These carnivores feed on sponges, corals, anemones, jellyfish, algae, and … sometimes other nudibranchs.

Adult nudibranchs are soft-bodied and have no shells, which makes them vulnerable to predators like crabs, sea stars, and fish. To protect themselves, some nudibranchs use camouflage. Others use chemicals that are toxic or bad-tasting to their predators. Some species take up toxins from their prey and use them in self-defense.

Nudibranchs come in the most amazing array of shapes and colors!

Can you find the matching pairs of nudibranchs?

Image credits: © tangatawhenua, © Danila Mansfield, © Dani Barchana, © Gareth Fee, © whodden, © chrisross, all (CC) BY-NC, via iNaturalist

Learn more

Dive deeper with these articles:

Natural History Museum UK: Why do sea slugs steal stings?
Australian Museum: Defensive colour in sea slugs

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