Loch's chromodoris

This small sea slug moves slowly over coral reefs. Loch's chromodoris grows to about 3 cm. It is a nudibranch, a sea slug with no shell, and it is worth a close look.

Also known as: chromodoris lochi, chromodoris lochi rudman, 1982, pyjama rainbow dorid

This species is easy to mix up with two close relatives, Chromodoris willani and Chromodoris dianae, which have the same blue-and-black colours. The best clue is the mantle: this species has one even colour with no white specks, while the look-alikes usually show white flecks.

This sea slug has a blue or blue-white body with a white edge all around it. Dark or black lines run along its back, called the mantle, and along its foot underneath. One line runs all the way around the edge of the mantle, just outside the rhinophores, the pair of horns on its head that it uses to sense its surroundings. A second line down the middle can be broken instead of solid. Its gills and rhinophores can pull in for safety. Their colour ranges from pale straw to pink or light orange.

It lives on coral reefs across the warm central Indo-Pacific, from Malaysia, Indonesia, and the Philippines to Fiji and northern Australia.

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  Black-margined Nudibranch

  Doriprismatica atromarginata

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  Blue dragon

  Glaucus atlanticus

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  Cratena Slug

  Cratena peregrina

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  Dotted Sea Slug

  Peltodoris atromaculata

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  Faithful Sea Slug

  Goniobranchus fidelis

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  Four-lined Polycera

  Polycera quadrilineata