Phyllidia coelestis nudibranch on blue background, Beqa Lagoon, Fiji.

beqa lagoon fiji melanesia oceania phyllidia coelestis sacoglossa animal animal markings animal themes aquatic blue blue background bumpy close up color image gastropod horizontal invertebrate living organism macro magnification marine biology mirrored image mollusk no people nudibranch one animal outdoors photography reflection science sea sea life sea slugs sea snails species tubercle underwater warty sea slugs wildlife yellow zoology