The plankton cell with a sniper's eye

摘要

It is perhaps the most extraordinary eye in the living world - so extraordinary that no one believed the biologist who first described it more than a century ago. Now it appears that the tiny owner of this eye uses it to catch invisible prey by detecting polarised light. This suggestion is also likely to be met with disbelief, for the eye belongs to a single-celled organism called Erythropsidinium. It has no nerves, let alone a brain. So how could it "see" its prey? Fernando Gomez of the University of Sao Paulo, Brazil, thinks it can. "Erythropsidinium is a sniper," he told New Scientist. "It is waiting to see the prey, and it shoots in that direction."