Body size matters for mate choice of the paradise fish

Initially, we employed a generalized linear model to explore the impacts of focal fish sex (i.e., focal male or female), stimulus fish size (i.e., small or large), and sex combination (i.e., different sex or same sex) on mate choice and same-sex preference behaviors in the paradise fish. In this model, focal fish sex (i.e., focal male or female), stimulus fish size (i.e., small or large), and sex combination (i.e., different sex or same sex) were used as fixed effects, while the percentage of time spent in the selected area was set as the dependent variable. The activity level (i.e., individual swimming speed and PTM) was incorporated as random effects. If the model indicated significant differences either among or within treatments, independent T-tests were conducted within a stimulus fish size treatment to compare the inter- or intra-treatment differences. Moreover, to delve deeper into the mate choice and same-sex preference behaviors of the paradise fish, we evaluated the strength of preference (SOP) between partners under different treatments (e.g., focal fish sex, stimulus fish size, and sex combination)

本研究首先采用广义线性模型（Generalized Linear Model），探究目标鱼性别（即雄性目标鱼或雌性目标鱼）、刺激鱼体型（即小型或大型）以及性别组合（即异性别或同性别）对天堂鱼的配偶选择与同性偏好行为的影响。该模型中，目标鱼性别、刺激鱼体型与性别组合作为固定效应（fixed effects），受试个体在选定区域内的停留时间占比作为因变量（dependent variable）；活动水平（即个体游泳速度与PTM）作为随机效应（random effects）纳入模型。若模型显示处理组间或组内存在显著差异，则在刺激鱼体型处理组内开展独立样本t检验（independent T-tests），以比较组间与组内差异。此外，为进一步深入探究天堂鱼的配偶选择与同性偏好行为，本研究还评估了不同处理条件下（如目标鱼性别、刺激鱼体型与性别组合）配对个体间的偏好强度（Strength of Preference，SOP）