Mar. 21, 2013 —
A modified version of an eye test used to assess visual acuity in the military
has been given to archerfish by scientists to help explain how these remarkable
fish are able to accurately spit down tiny insects high above the water's
surface.
 |
An archerfish (Toxotes chatareus) spitting
at the letter C in a modified Landolt C test,
which is used to measure visual acuity
(Credit: Dr Shelby Temple)
|
Dr Shelby
Temple, now at the University of Bristol , and his team at the University
of Queensland and the University of Western Australia
The
researchers first trained the fish to spit at one of two letters -- an 'O' or a
'C' -- by rewarding them with food. Then they showed them small versions of
both letters together and recorded which letter they spat at.
Dr Temple
said: "This modified Landolt C test works because the only difference
between the two letters is the gap in the 'C' so in order to tell the
difference and spit at the right target to get their reward the fish must be
able to resolve the gap."
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