From: JosephEPJP@aol.com
Date: Sun, 9 Mar 1997 17:15:31 -0500 (EST)
To: n.patenaude@auckland.ac.nz, pita@whale.simmons.edu,
krill@whale.simmons.edu
Subject: Blue Whale Eyes
My daughter is researching whales for a project in school. She would like to
know the size of a blue whale's eye. Thank you.
I don't study physiology but I'll give it my best shot. Vision generally doesn't play an
important a role in whales because visibility under water is so much poorer than on land.
Thus, whales have relatively small eyes compared to their body size. Nevertheless their
eyes are pretty big. Right whale eyes are about the size of an orange, while blue whales
eyes are probably one and a half times bigger.
To function at all, whale and dolphin eyes have to undergo adaptations to their aquatic
environment. For instance, they don't need to keep their eyeballs wet (because they are
already in water) so they lack lacrymal glands (those glands that produce tears). In other
words whales can't cry. They also need not worry about dust and so don't have eyelashes.
The smallest cetacean eye is that of the Ganges river dolphin. This dolphin feeds off the
muddy bottom of rivers where eyesight doesn't help much. Its eye is really small, about as
big as a pea.
Nathalie Patenaude
Molecular Ecology and Evolution Group
School of Biological Sciences
Private Bag 92019
University of Auckland
Auckland, New Zealand
Ph: 649 373 7599 ext 4588
Fax: 649 373 7417