Data for: Multiple behavioral mechanisms shape development in a highly social cichlid fish

Early-life social experiences shape adult phenotype, yet the underlying
behavioral mechanisms remain poorly understood. We manipulated early-life
social experience in the highly social African cichlid fish Astatotilapia
burtoni to investigate the effects on behavior and stress axis function in
juveniles. Juveniles experienced different numbers of social partners in
stable pairs (1 partner), stable groups (6 fish; 5 partners), and
socialized pairs (a novel fish was exchanged every 5 days; 5 partners).
Treatments also differed in group size (groups vs. pairs) and stability
(stable vs. socialized). We then measured individual behavior and
water-borne cortisol to identify effects of early-life experience. We
found treatment differences in behavior across all assays: open field
exploration, social cue investigation, dominant behavior, and subordinate
behavior. Treatment did not affect cortisol. Principal components (PC)
analysis revealed robust co-variation of behavior across contexts,
including with cortisol, to form behavioral syndromes sensitive to
early-life social experience. PC1 (25.1 %) differed by social partner
number: juveniles with more partners (groups and socialized pairs) were
more exploratory during the social cue investigation, spent less time in
the territory, and were more interactive as dominants. PC5 (8.5 %)
differed by stability: socialized pairs were more dominant, spent less
time in and around the territory, were more socially investigative, and
had lower cortisol than stable groups or pairs. Observations of the home
tanks provided insights into the social experiences that may underlie
these effects. These results contribute to our understanding of how
early-life social experiences are accrued and exert strong, lasting
effects on phenotype.

生命早期的社会经历会塑造成体表型，但其背后的行为调控机制仍有待深入阐明。我们以高度社会化的非洲慈鲷（African cichlid fish）伯顿朴丽鱼（Astatotilapia burtoni）为实验模型，对其生命早期的社会经历进行人工操控，以探究该经历对幼体行为与应激轴（stress axis）功能的影响。实验设置了三种社会伴侣数量条件：稳定配对组（仅1尾社会伴侣）、稳定群养组（6尾个体，即拥有5尾社会伴侣）、社交轮换配对组（每5日更换1尾陌生个体作为伴侣，即拥有5尾社会伴侣）。各组间在群体规模（群养vs配对）与环境稳定性（稳定组vs社交轮换组）两个维度上均存在差异。后续我们通过测定个体行为指标与水体皮质醇（water-borne cortisol）水平，以解析生命早期社会经历的调控效应。结果显示，所有行为测试范式下均存在处理组间的行为差异，涵盖旷场探索、社会线索探查、优势行为与从属行为四类测试。但不同处理组的皮质醇水平未出现显著差异。主成分分析（Principal components，PC）结果表明，不同情境下的行为（包括与皮质醇相关的行为）存在显著共变关系，进而形成了对生命早期社会经历敏感的行为综合征（behavioral syndromes）。主成分1（PC1，贡献率25.1%）的差异与社会伴侣数量相关：拥有更多社会伴侣的幼鱼（群养组与社交轮换配对组）在社会线索探查实验中探索性更强，领地停留时间更短，且作为优势个体时互动性更高。主成分5（PC5，贡献率8.5%）的差异与环境稳定性相关：相较于稳定群养组与稳定配对组，社交轮换配对组的幼鱼表现出更强的优势行为，领地内外停留时间更短，社会探查行为更频繁，且皮质醇水平更低。对饲养缸的日常行为观测为解析上述效应背后的社会经历机制提供了重要线索。本研究结果有助于深化我们对生命早期社会经历的积累过程，以及其如何对生物体表型产生强烈且持久调控作用的理解。