Ishihara Hikaru, Kanda Shinji
Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan.
iScience. 2024 Dec 12;27(12):111490. doi: 10.1016/j.isci.2024.111490. eCollection 2024 Dec 20.
Animals exhibit colorations optimal for their niche, which hides their existence from other organisms. In Apogoninae fishes, the father broods their egg inside their mouth. Since the color of eggs is different from parental fish, it can disrupt the optimal camouflage coloration of parental fish if the lower jaw is transparent. Here, we identified male- and breeding season-specific whitish coloration consisting of iridophores in the lower jaw. Artificial implantation of eggs inside the mouth of females and males showed that iridophores in the lower jaws concealed the conspicuous coloration of eggs only in males. In addition, it was revealed that iridophore development in the lower jaw is induced by androgen through the Alkal-Ltk pathway. These results suggest that androgen-dependent breeding colorations in males, which have been considered to attract females, may serve the opposite function, "inconspicuous breeding coloration" in these species.
动物呈现出与其生态位相适应的颜色，这种颜色能使其不被其他生物发现。天竺鲷科鱼类中，雄性会将卵含在口中孵化。由于卵的颜色与亲鱼不同，如果下颌是透明的，就会破坏亲鱼的最佳伪装色。在此，我们发现雄性天竺鲷在繁殖季节时，下颌会出现由反光色素细胞构成的白色。对雌性和雄性天竺鲷进行人工口腔内植卵实验表明，只有雄性天竺鲷下颌中的反光色素细胞能掩盖卵的明显颜色。此外，研究还发现，雄激素通过Alkal-Ltk信号通路诱导下颌中反光色素细胞的发育。这些结果表明，雄性天竺鲷中依赖雄激素的繁殖色，以往被认为是用于吸引雌性，而在这些物种中可能起到相反的作用，即“不显眼的繁殖色”。
