Ask A Scientist© Biology Archive

name         Lori
status       student
age          20s

Question -   In terrestrial environments, vertebrate prey species
tend to have lateral placement of the eyes, allowing them to have
panoramic vision.  Terrestrial predators, on the other hand, have
frontally places eyes, allowing for binocular vision and better depth
perception.  In marine environments, both aquatic predator and prey
species have laterally placed eyes; why is this so?
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This is only a theory as it's hard to prove a "why" for evolution.  In an
aquatic environment, it's much more difficult to do a lateral rotation
because of the fluid density.  Frontal eye placement would require greater
rotation to keep the prey in view as it darts to one side or the other.

Don
Donald Yee Ph.D.                San Francisco Estuary Institute
180 Richmond Field Station,     1325 South 46th St. Richmond, CA  94804
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