Sea Urchin Body Acts as a Giant Eye

From Treehugger:

Sea urchins don’t have eyes as we think of them: a pair of orbital organs attached to a brain. In fact, as far as researchers can tell, sea urchins don’t have brains at all. Instead, they use a distributed nervous system in which each part responds to local stimulus. Still, scientists have long wondered how these spiny creatures could be so adept at avoiding predators and finding dark corners without dedicated organs for sight. Through careful genetic analysis, marine biologists have discovered light-sensitive molecules concentrated along urchin spines. Sönke Johnsen, who led the research, explained that, “it looks like the entire surface of their bodies are acting as one big eye.”

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