Kozlowski, C.P.*; McIntyre, J.C.; Moore, P.A.: The Winning Effect in Agnostic Encounters of Crayfish is a Time Dependment Phenomenon

Previous studies have shown that fighting behavior is the fundamental method for determining dominance between crayfish. Many factors are responsible for determining dominance, including the crayfish’s previous fighting experiences. It has been shown that a crayfish that has had a previous winning experience by fighting another crayfish is more likely to win its next fight. This is termed the “winning effect”. In this experiment, we tested how long this winning effect lasted by varying the time between a crayfish’s winning experience and its next fight. Results showed that the longer the time delay between the two fights, the more likely the crayfish was to initiate a fight, but the less likely it was to win the fight. We conclude that while previous fighting experiences do influence a crayfish’s likelihood of initiating and winning a fight, this effect is temporary and decreases rapidly with time. This time period is between forty and sixty minutes in length. The period in which the “winner effect” takes place can play an important role in dominance and hierarchy formation. Further research needs to take into account the time between previous fighting experiences in order to assess a crayfish’s chances of winning a fight accurately.