Yet another example of society's underestimation of another species.
'DIDN'T YOU PUMMEL ME?'
Crayfish may be small, but they aren't stupid. After losing a fight they can
remember who beat them, and may use that information to steer clear of another
fight against the same opponent.
Australian researchers studied fights between males of an aggressive species
of freshwater crayfish, Cherax dispar. Like most crayfish, C. dispar fights by
locking claws with its opponent and holding on until one creature gives up and
The crayfish with the stronger claws almost always wins a first fight and, in
subsequent fights with the same crayfish, it keeps winning, The loser often
slinks away without even fighting. The researchers, Frank Seebacher of the
University of Sydney and Robbie S. Wilson of the University of Queensland,
wanted to see whether in those subsequent fights the loser just blindly leaped
into the fray again or recognized that it was up against a superior opponent.
In their experiments, described in Biology Letters, they disabled the claws
of the winner of the first fight by supergluing them shut and let the two
crayfish go at each other a half-hour later and 24 hours later. Even with its
claws disabled, the winner of the first fight kept winning, indicating that the
loser somehow remembered that the winner was stronger.
This "winner effect" is not unknown, but the researchers say it seldom
persists as long as 24 hours. They suggest that it may be advantageous for a
crayfish to remember how it fared in a previous fight -- to avoid additional
fights, which are costly in terms of energy use, not to mention potential