Figure 4. Effect of mianserin on agonistic bouts.

A, Winning rates of dominant small crayfish injected mianserin at various concentrations in pairings with naive large crayfish are plotted. Mianserin was injected into dominant animals immediately after establishment of dominant-subordinate formation, and then paired with naive large crayfish after overnight isolation. Asterisks indicate that the winning rate differed significantly (Fisher’s exact test, *p<0.05). B, The number of fights of pairings during the first 30 min of agonistic bouts. C, The average duration of individual fights of pairings during the first 30 min of agonistic bouts. In B and C, data of pairings between dominant small and naive large animals (Left) are from Fig. 2 that sum the data of both winning and losing dominant small crayfish. On the right, 20 and 50 µM mianserin injected into dominant small crayfish are also summed. The asterisk in C indicates that the number of fights differed significantly (Mann-Whitney rank sum test, **p<0.01). D, Effect of timing of mianserin injection into dominant small crayfish after establishment of social rank. The percentages of winning outcomes of agonistic bouts of mianserin-injected small crayfish are plotted. E, Effects of mianserin-injected naive large crayfish 1 hr or 10 min before pairing with naive small crayfish. The percentages of winning outcomes of agonistic bouts of mianserin-injected naive large crayfish are plotted as black bars and those of untreated naive small crayfish are plotted as grey bars.