Signaling cascades and the importance of moonlight in coral broadcast mass spawning

Many reef-building corals participate in a mass-spawning event that occurs yearly on the Great Barrier Reef. This coral reproductive event is one of earth's most prominent examples of synchronised behavior, and coral reproductive success is vital to the persistence of coral reef ecosystems. Although several environmental cues have been implicated in the timing of mass spawning, the specific sensory cues that function together with endogenous clock mechanisms to ensure accurate timing of gamete release are largely unknown. Here, we show that moonlight is an important external stimulus for mass spawning synchrony and describe the potential mechanisms underlying the ability of corals to detect environmental triggers for the signaling cascades that ultimately result in gamete release. Our study increases the understanding of reproductive chronobiology in corals and strongly supports the hypothesis that coral gamete release is achieved by a complex array of potential neurohormones and light-sensing molecules.

许多造礁珊瑚（reef-building corals）会参与每年在大堡礁发生的大规模产卵事件。此类珊瑚繁殖事件是地球最具代表性的同步行为范例之一，而珊瑚繁殖成功对于珊瑚礁生态系统的存续至关重要。尽管已有多项环境线索被认为与大规模产卵的时间调控相关，但与内源生物钟机制协同作用、以确保配子释放时机精准的特定感官线索，在很大程度上仍未明确。本研究证实，月光是实现大规模产卵同步性的关键外部刺激因素，并阐明了珊瑚感知环境触发因子、进而启动最终导致配子释放的信号级联反应的潜在机制。本研究加深了人们对珊瑚繁殖时间生物学（reproductive chronobiology）的认知，并有力支持了这一假说：珊瑚的配子释放是由一系列潜在的神经激素与光感受分子共同介导完成的。