Collaborative Research: Spawning and Fertilization in the Caribbean Coral Montastraea Annularis Sensu Lato

Montastraea Cirularis复合体的成员是加勒比海主要的造礁珊瑚，它们一直是研究珊瑚礁生态和地质的模式系统。已描述了三个分类群(M annularis、M ftanksi和M aveolata)，尽管它们作为单独的物种的地位受到了质疑。自20世纪80年代S以来，这些珊瑚和其他几种珊瑚在许多地点急剧减少。为了使环纹夜蛾持久存在和恢复，它必须繁殖。然而，几乎对这种或任何加勒比海珊瑚的繁殖成功知之甚少。这项建议的主要重点是提供一个全面的了解产卵行为，配子亲和性和受精率的三个成员的环带。以前从巴拿马收集的数据表明，产卵时间和配子兼容性的差异足以维持三个分类群之间的生殖边界。这些障碍还有一个额外的后果，那就是增加了许多礁石上潜在伴侣之间的距离。田间受精率似乎很低，很可能是因为产卵同种之间的距离。自交系一般不会成功。初步工作已经建立了收集这些类型数据的研究方案，但在一系列产卵条件下收集大量数据还在前面。我们建议通过在巴拿马的一个五年计划来实现这一目标。实验室实验将确定配子寿命和配子浓度如何影响受精成功。这为确定异步繁殖的后果提供了重要信息。实地研究将记录每个分类群的产卵时间，以及产卵事件期间水柱中的受精率和配子浓度。模拟配子扩散的Drogues将被用来确定在各种条件下的扩散模式，以便更好地理解配子如何从珊瑚礁平流。这项工作将提供关于任何加勒比硬珊瑚就地受精成功率和影响受精率的机制的第一批信息。这种物种对珊瑚礁群落的重要性，以及最近这种珊瑚数量的下降，使得拟议的研究更加及时。

Members of the Montastraea annularis complex are the major reef building corals in the Caribbean, and they have been a model system for studies of the ecology and geology of coral reefs. Three taxa have been described (M annularis, M ftanksi and M faveolata), although their status as separate species has been questioned. Since the 1980's, these corals, along with several others, have declined drastically in abundance at many sites. In order for M annularis to persist and recover, it must reproduce. However, almost nothing is known about the reproductive success of this or any Caribbean coral. The major focus of this proposal is to provide a comprehensive understanding of the spawning behavior, gamete compatibilities and fertilization rates of the three members of the M annularis complex. Data collected previously from Panama suggest that differences in spawning times and gametic compatibility are sufficient to maintain reproductive boundaries among the three taxa. These barriers have the additional consequence of increasing the distance between potential mates on many reefs. Fertilization rates in the field appear to be quite low, most likely because of the distances between spawning conspecifics. Selfed crosses are generally unsuccessful. Preliminary work has established research protocols for collecting these types of data, but the bulk of the data collection over a range of spawning conditions lies ahead. We propose to accomplish this through a five-year program in Panama. Laboratory experiments will determine how gamete longevity and gamete concentration influence fertilization success. This provides important information for determining the consequences of asynchronous spawning. Field studies will document the spawning times of each taxon and the fertilization rates and gamete concentrations in the water column during spawning events. Drogues that simulate gamete dispersal will be used to determine the patterns of dispersal under a variety of conditions in order to get a more robust understanding of how gametes can be advected from the reef. This work will provide the first information on in situ rates of fertilization success and the mechanisms that influence fertilization rates for any Caribbean hard coral. The importance of this species to coral reef communities and the recent declines in this coral make the proposed study all the more timely.