Data on dyadic male contests

Data represents male aggressive behaviors during contests staged between pairs of males in a small test tank measuring 30 × 20 × 20 cm. We focused on three frequent aggressive behaviors: (1) S-position: this threat display usually initiates a fight. Males swim in a parallel or anti-parallel position and bend their bodies in an S-shaped manner with all unpaired fins erect; (2) tail-beats: S-positions are often followed or superimposed by tail-beats, which are fast movements of head and tail in opposing directions that either touch the opponent’s body or send shock waves to the opponent; and (3) bites – we defined all incidences of ramming and bite-like attacks as bites, because both these behaviors occur extremely quickly and thus are indistinguishable to the human eye. We also recorded fight duration until dominance was established. If no dominance was established within 10 minutes of the first interaction, we terminated the fight; those trials were discarded from the analysis of fighting durations, while fight durations were scored as “0” when no aggressive behavior occurred at all (those trials were terminated after a total of 15 minutes of observation). SL of both contestants was taken after a contest by laying the fish flat on plastic foil-covered millimeter paper.

本数据集收录了在小型测试水族箱（尺寸为30 × 20 × 20厘米）中，由雄性个体间上演的竞赛过程中的雄性攻击性行为数据。研究重点聚焦于三种常见的攻击性行为：一是S形姿势：此类威胁性展示通常为战斗的导火索。雄性个体以平行或反平行姿势游动，并弯曲身体呈S形，所有成对鳍部均竖立；二是尾部击打：S形姿势常被尾部击打所继起或叠加，表现为头部与尾部在相反方向上的快速运动，可能触及对手身体或向对手发出冲击波；三是咬击——我们将所有冲撞和类似咬击的行为定义为咬击，因为这两种行为发生极为迅速，以至于肉眼难以辨识。此外，我们还记录了直至确立统治地位的战斗持续时间。若在首次互动后的10分钟内未确立统治地位，则终止战斗；此类试验被排除在战斗持续时间分析之外，而若整个观察期间未发生任何攻击性行为，则战斗持续时间计为“0”（此类试验在总计15分钟的观察后终止）。在竞赛结束后，通过将鱼类平铺于塑料薄膜覆盖的毫米纸上，对双方参赛者的身体长度（SL）进行测量。