Jellyfish have eyes AND brains!

A great article in the NYT by Natalie Angier about the surprising complexity of jellyfish:

For all their noble antiquity, jellyfish have long been ignored or misunderstood by mainstream science, dismissed as so much mindless protoplasm with a mouth. Now, in a series of new studies, researchers have found that there is far more complexity and nuance to a jellyfish than meets the eye — or eyes. In the May 10 issue of the journal Current Biology, Dr. Garm and his colleagues describe the astonishing visual system of the box jellyfish, in which an interactive matrix of 24 eyes of four distinct types — two of them very similar to our own eyes — allow the jellies to navigate like seasoned sailors through the mangrove swamps they inhabit.

In The Journal of Experimental Biology, Richard A. Satterlie, a marine biologist at the University of North Carolina Wilmington, recently disputed the conventional wisdom that jellyfish lack any semblance of the central nervous system that we higher vertebrates are so proud of. The distribution of a jellyfish’s nerve cells may be comparatively more diffuse than in an animal with an obvious brain and spinal cord, said Dr. Satterlie, but the layout is hardly helter-skelter. Recent detailed investigations of jellyfish neural architecture and activity reveal evidence of “neuronal condensation,” places where the neurons coalesce to form distinctive structures that act as integrating centers — taking in sensory information and translating it into the appropriate response.

“The bottom line is, jellyfish do a lot more than people think,” said Dr. Satterlie, “and when college textbooks claim they have no centralized nervous system, that’s flat-out wrong.”  Dr. Albert goes further, insisting it is fair to declare that a jellyfish has a brain.

Read it all here.

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