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

Montastraea annularis复合体的成员是加勒比地区主要的造礁珊瑚，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 faveolata），尽管它们作为单独物种的地位受到质疑。自20世纪80年代以来，这些珊瑚，沿着其他几种珊瑚，在许多地点的数量急剧下降。为了使M annularis持续存在和恢复，它必须繁殖。然而，几乎没有人知道这种或任何加勒比珊瑚的繁殖成功。 该建议的主要重点是提供一个全面的了解的产卵行为，配子相容性和受精率的三个成员的M annularis复杂。以前从巴拿马收集的数据表明，产卵时间和配子相容性的差异足以维持三个类群之间的生殖界限。这些障碍物还有一个额外的后果，就是增加了许多珊瑚礁上潜在配偶之间的距离。在该领域的受精率似乎是相当低的，最有可能是因为产卵同种之间的距离。自花杂交通常不成功。 初步工作已经确立了收集这类数据的研究协议，但在一系列产卵条件下收集大部分数据的工作还有待完成。我们建议通过巴拿马的一个五年方案来实现这一目标。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。这为确定异步派生的结果提供了重要信息。实地研究将记录每个分类群的产卵时间以及产卵期间水柱中的受精率和配子浓度。模拟配子扩散的Drogues将用于确定在各种条件下的扩散模式，以便更好地了解配子如何从珊瑚礁平流。这项工作将提供有关任何加勒比硬珊瑚的原地受精成功率和影响受精率的机制的第一批资料。这一物种对珊瑚礁群落的重要性以及最近这种珊瑚的减少使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.