While we may call them sea slugs, these diverse and colorful gastropods look like they've come from another planet, a place of brilliant oranges, greens, and blues, where even camouflage is beautiful.
These colorful, soft and shell-less nudibranchs are using camouflage to hide, but some of them are poisonous or use aposematic (warning) coloration to shock potential predators.
Chromodoris willani, found in the Western Pacific Ocean
(via Steve Childs)
Halgerda batangas, with a network of orange lines, can be found in the tropical Western Pacific
(via Steve Childs)
Armina semperi, lives in Indo-West Pacific
(via Ria Tan)
Nembrotha kubaryana, with green stripes or green raised spots, occurs in the tropical Indo-West Pacific
(via Klaus Stiefel and Bernard Dupont)
Chromodoris annae, found in the central area of the Indo-Pacific region
(via Bernard Dupont and Raymond)
Cuthona flavovulta
(via Ken-Ichi Ueda and John Albers-Mead)
Ceratosoma brevicaudatum, lives in the tropical waters of Western Australia, New South Wales and around Tasmania
(via erikschlogl, Geoff Rollins, Klaus Stiefel and Saspotato)
Jorunna funebris, occurs in the Red Sea and in the Indian Ocean
(via Ria Tan and Daniel Kwok)
Phyllodesmium longicirrum, a solar-powered (it has photosynthetic zooxanthellae) sea slug, known from the West Pacific
(via Silke Baron and Jason Marks)
Phyllodesmium iriomotense
(via Steve Childs)
Hypselodoris kanga, distributed from the Western Indian Ocean to Hong Kong
(via Steve Childs and budak)
Chromodoris orientalis, from the Indo-West Pacific
(via crawl_ray)
Bornella anguilla, lives in the waters of the Indo-West Pacific
(via Min Sheng Khoo)
Phyllidia varicosa, lives in the Indo-West Pacific, Central Pacific and the Red Sea
(via Bernard Dupont and Taso Viglas)
Glaucus atlanticus, also known as the sea swallow or blue dragon, can be found in the East and South Coast of South Africa, European waters and the east coast of Australia and Mozambique
(via Sylke Rohrlach and Kehan Herman)
Chromodoris reticulatus, a sea slug with a detachable penis
(via Bernard Dupont)
Cuthona yamasui, lives in the waters of Indo-West Pacific
(via Nick Hobgood and Vishal Bhave)
Thecacera pacifica, lives in the waters of Western Pacific and Indian Ocean
(via Nemo's great uncleand crawl_ray)
Flabellina exoptata, lives in the Indo-West Pacific
(via Steve Childs and Silke Baron)
Miamira sinuata, lives in the Indo-Pacific
(via Ria Tan)
Pteraeolidia ianthina, also known as the blue dragon, found in the Western Pacific Ocean and in the Red Sea
(via Richard Ling, Ria Tan and Sylke Rohrlach)