Editor's Summary
12 May 2005
Missing link?
Cubozoans, or box jellyfish, each have twenty-four eyes of four types, but no central brain for information processing. An investigation of these eyes reveals optics as sophisticated as in vertebrates. Despite this, the retina is out of focus and the sharp image is not used to provide acute vision, but as a way of processing visual information. 'Blurred' vision may be perfect for avoiding large stationary objects without focusing on small floating objects and plankton. This may also be a pointer to a missing link in the early evolution of animal visual systems, likely to have involved eyes performing a single visual task only. The cover shows the two lens eyes and two pairs of pigment pit eyes in the bizarre sensory club of Chiropsalmus sp., larger but similar to those of Tripedalia cystophora used in the optical study.
News and Views: Sensory physiology: Brainless eyes
The visual equipment of box jellyfish includes eight optically advanced eyes that operate with only a rudimentary nervous system. As they produce blurred images, their function remains an open question.
Rüdiger Wehner
doi: 10.1038/435157a
Letter: Advanced optics in a jellyfish eye
Dan-E. Nilsson, Lars Gislén, Melissa M. Coates, Charlotta Skogh and Anders Garm
doi: 10.1038/nature03484