Underwater
computer gaming has reached the fish tanks in the laboratories of the
biologists. Not through a piscatorial interest I hasten to add, but to study
the predatory instinct of their fish.
Ioannou
et al chose the bluegill sunfish to play their new computer game of hunt and
catch (1, 2). In the wild a bluegill sunfish will eat lots of insect larvae as
well as small crustaceans. It sneaks up and sucks them in when they least expect
it like a salesman on a car lot. Young ones go after water fleas and rotifers.
Their
computer game consists of projecting reddish dots onto a screen in the tank,
which the fish take for prey and sneak up to suck them in. Of course it would be
no fun if they were easy to hunt and get close to, so they are more challenging
than that. Also, they are not just offered one at a time.
They
are presented with a small army of red dots for them to try and chase down to
attack and devour. Now on occasion, real insect larvae and water fleas will
move around independently, but not always. They can start to herd and move
along in group motion and now the question is what do the bluegills think about
that?
The
answer is that they don’t care for it. This isn’t what you want your prey to
do. Ganging up is going to make any self-respecting bluegill uneasy and they
leave well alone. They expect their lunch bites to be doing their own thing and
will look for the individual who eschews the crowd to wander off on their own.
Up
until now the study of predatory hunting has been a little hit or miss as the
prey are not under the control of the experimenter. Now with the development of
virtual prey, complete control of the experiment is possible and the effects of
natural prey behavior can be simulated repeatedly and the predator’s response
monitored systematically.
What
isn’t recorded in the write-ups of the game play is the attention span of the
bluegills. Do they become addicted or do they just dabble?
- http://www.sciencemag.org/content/early/2012/08/15/science.1218919
- http://www.bbc.co.uk/news/technology-19368532
