FISH WIN FIGHTS ON STRENGTH OF PERSONALITY
Scientists at the
University of Exeter and Texas A&M University Found that When Fish Fight
Over Food, it is Personality, Rather than Size, that Determines Whether They
Will be Victorious.
Science Daily, April 26, 2013
When predicting the outcome of a fight, the big guy doesn't always win
suggests new research on fish. Scientists at the University of Exeter and
Texas A&M University found that when fish fight over food, it is
personality, rather than size, that determines whether they will be
victorious. The findings suggest that when resources are in short supply
personality traits such as aggression could be more important than strength
when it comes to survival.
The study, published in the journal Behavioral Ecology and Sociobiology,
found that small fish were able to do well in contests for food against
larger fish provided they were aggressive. Regardless of their initial size,
it was the fish that tended to have consistently aggressive behaviour -- or
personalities -- that repeatedly won food and as a result put on weight.
Dr Alastair Wilson from Biosciences at the University of Exeter said:
"We wondered if we were witnessing a form of Napoleon, or small man,
syndrome. Certainly our study indicates that small fish with an aggressive
personality are capable of defeating their larger, more passive counterparts
when it comes to fights over food. The research suggests that personality
can have far reaching implications for life and survival."
sheepshead swordtail fish (Xiphophorus birchmanni) fish were placed in pairs
in a fish tank, food was added and their behaviour was captured on film. The
feeding contest trials were carried out with both male and female fish. The
researchers found that while males regularly attacked their opponent to win
the food, females were much less aggressive and rarely attacked.
animals, personality is considered to be behaviour that is repeatedly
observed under certain conditions. Major aspects of personality such as
shyness or aggressiveness have previously been characterised and are thought
to have important ecological significance. There is also evidence to suggest
that certain aspects of personality can be inherited. Further work on
whether winning food through aggression could ultimately improve
reproductive success will shed light on the heritability of personality