Male guppies display an outstanding diversity of color patterns which is formed as a result of a complex interplay between sexual selection, predation, and other environmental factors. The heterogeneity of the environment affects the variability of ornamental traits in male guppies through genotype–environment interaction. Thyroid hormones (THs) are important regulators of the ontogeny of fish and serve as a link between environmental changes and phenotypic development. However, the role of THs in the formation of a variety of color patterns in male guppies remained poorly understood. In this work, an experimental assessment of the effect of THs on the variability of ornamental traits in Poecilia wingei males was carried out. The fish were reared from birth to the initial stages of the formation of melanistic elements in males and until the final formation of the color pattern; they were subjected to different hormonal regimes: euthyroidism (natural TH status), hyperthyroidism (high TH level, at a triiodo-L-thyronine concentration of 0.15 μg/mL), and hypothyroidism (TH-deficiency, at a thiourea concentration of 0.025%). Alterations in the TH status caused changes in the timing and rate of the development of coloration and affected the transformation of various elements of the color pattern in males. These changes led to an increase in phenotypic variability and the appearance of ornamental traits in the male color patterns that were characteristic of closely related species of Poecilia. Thus, the data obtained indicate a potentially important role of thyroid hormones in the diversification of guppy color patterns and open up new prospects for studying the role of endocrine regulatory mechanisms in the adaptive evolution of poeciliid fish.

由于性选择、捕食和其他环境因素之间复杂的相互作用，雄性孔雀鱼表现出出色的颜色图案多样性。环境的异质性通过基因型-环境相互作用影响雄性孔雀鱼观赏性状的变异性。甲状腺激素 (THs) 是鱼类个体发育的重要调节剂，是环境变化和表型发育之间的纽带。然而，对 THs 在雄性孔雀鱼各种颜色图案形成中的作用仍然知之甚少。在这项工作中，对 THs 对Poecilia wingei观赏性状变异性影响的实验评估进行了男性。这些鱼从出生到雄性黑色素元素形成的初始阶段一直被饲养，直到最终形成颜色图案；他们接受了不同的激素治疗：甲状腺功能正常（自然 TH 状态）、甲状腺功能亢进（高 TH 水平，三碘-L-甲状腺氨酸浓度为 0.15 μg/mL）和甲状腺功能减退症（TH 缺乏，硫脲浓度为 0.025% ）。TH 状态的改变导致着色发生的时间和速度发生变化，并影响雄性颜色模式中各种元素的转化。这些变化导致表型变异性的增加和雄性颜色图案中装饰性状的出现，这些特征是Poecilia密切相关物种的特征. 因此，获得的数据表明甲状腺激素在孔雀鱼颜色模式多样化中的潜在重要作用，并为研究内分泌调节机制在孔雀鱼适应性进化中的作用开辟了新的前景。