Image from en.wikipedia.org, licensed with GFDL. Original description follows:

Goby fish (Amblyeleotris sp.) and shrimp (Alpheus sp.) in front of their burrow. The fish and the shrimp live together in a Symbiotic relationship where the shrimp digs and cleans up a burrow and the fish warn the almost blind shrimp against predators.

The picture has a blueish tint over it, because it was taken without a flash at 15 meters below sea level. At these depths this is what the world actually looks like; one needs a flash or torchlight to see the colors that are filtered out by the water.

Picture taken by Jan Derk in April 2004 in Koh Tao, Thailand.

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