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Sea Sapphire — printable fact sheet
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Sea Sapphire
Sapphirina metallina
Sea sapphires are copepods of the genus Sapphirina, tiny drifting crustaceans a few millimetres long that produce some of the most intense colour in the ocean and then vanish outright. Only the males are coloured. Their backs carry stacked layers of hexagonal guanine crystals se…
Did you know?
- Sea Sapphires are among the few animals whose coloration is produced entirely by optical interference, not pigments.
- The layer spacing in a sea sapphire's guanine stack differs between species, so different species flash different colours. When the angle of incidence passes a threshold, the reflected light shifts into the ultraviolet and the copepod becomes effectively invisible to human eyes and to most fish. Females lack the crystal stacks entirely but have enormous eyes, consistent with the flashing being a mating signal. Copepods as a group are thought to be the most numerous multicellular animals on Earth, outnumbering all insects combined.
What I learned
Draw the sea sapphire
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