Influences of Prior Agonistic Experiences On Aggression Measures in the Male Swordtail (Xiphophorus Helleri)

摘要: The influences of prior agonistic experience on the aggressive behaviour swordtail males were studied in standardized aggression tests. In "standard-opponent" test subject fights against a much smaller opponent behind transparent partition, whereas mirror it attacks its own image. Both tests are appropriate to measure mean biting rates an adequate sample individuals. If reproducible estimates aggressiveness single individuals needed, is most method, for gives correlation coefficients up 0.96 between first and second measurement. When fish had been involved series escalating activities without final decision encounters, subsequent their frequencies elevated at least 24 h after last fight. Winning rank order fight led increase losing decrease frequency later. By contrast, social settlement long-term stabilized hierarchy relation totally reversed: Dominant showed lower than subordinate test. hypothesis proposed that even under natural conditions high ranking tend use energy potential more economic way low males. existence rank-dependent fighting strategies could be due differences risk: dominant extremely risky because they can lose status, which inevitably would lead lowered genetic fitness, actions not very status anyway.