How do tropical fish recognize season? A comparative approach of tropical monsoon around the equator

本研究的目的是澄清与热带鱼生殖活动有关的环境因素，并研究将环境刺激转化为内部信号的可能机制。本研究中使用的两种棘足动物的生殖周期与热带季风密切相关。在产卵季节，每个物种在物种选择的月相附近产卵。我们还关注了时钟基因（Cry）在金纹旋足下丘脑中的表达。该基因的表达模式随着月亮周期的变化而波动，并在第一个季度左右达到峰值，这表明时钟基因与包括生殖在内的月亮相关活动的振荡有关。

The aim of the present study was to clarify environmental factor(s) in relation to reproductive activity in tropical fish and to examine a possible mechanism that transduces environmental stimuli into the internal signal. Two spinefoots species used in the present study had a clear reproductive cycle that is closely correlated with tropical monsoon. During the spawning season, each species spawned around the species-selective lunar phase. We also focused on the expression of clock gene (Cry) in thehypothalamus of the goldlined spinfoot. The expression pattern of this gene fluctuated with lunar cycle and peaked around the first quarter moon, suggesting that clock genes is related to oscillation of lunar-related activity including reproduction.