Scleractinian corals are modular colonial organisms and are the main framework builders of coral reefs. Most corals reproduce by broadcast spawning with external fertilization and these processes are essential to replenish reef coral populations. Despite decades of research, many aspects of coral reproductive biology remain poorly studied. For example, two important reproductive life history traits, colony size and age at the onset of sexual maturity, are mostly unknown for many reef-building corals. In this study, wild colonies of different size classes and colonies of a known age (i.e. colonies sexually cultured and reared from larvae to adults) of the massive scleractinian Favites abdita were examined for the presence or absence of mature oocytes to determine size and age at the onset of sexual reproduction. Fecundity at the onset of reproductive maturity across size classes of wild colonies was also determined. Surveyed and sampled colonies were grouped into three size classes based on maximum colony diameter (A = 0.1-4.0 cm, B = 4.1-8.0 cm, and C = >8.1 cm). For both wild and sexually propagated colonies, the smallest colonies containing gametes were 1.8 cm in diameter, suggesting that this is the minimum colony size at onset of sexual maturity. Colonies of size class A had lower mean oocyte counts per polyp (44 ± 6.08; mean ± SE) compared to colonies of classes B and C (469 ± 62.41, 278 ± 57.15, respectively). However, mean oocyte geometric mean diameter of size class A colonies was greater (340.38 ± 7.68 μm) than classes B and C (283.96 ± 6.94 μm, 317.57 ± 9.18 μm, respectively). Results of this study bring in to question the widely applied operational definition of coral juveniles being colonies ≤4.0 cm diameter and suggest that even quite small colonies may play a role in contributing to the natural larval pool on reefs than previously thought.

中文翻译：

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菲律宾西北部性繁殖和野生Favites abdita菌落的性成熟开始

巩膜珊瑚是模块化的殖民生物，是珊瑚礁的主要框架建设者。大多数珊瑚通过外部施肥的繁殖产卵繁殖，这些过程对于补充珊瑚礁珊瑚种群至关重要。尽管进行了数十年的研究，但珊瑚生殖生物学的许多方面仍然研究不足。例如，对于许多造礁珊瑚来说，两个重要的生殖生活史特征，即性成熟开始时的菌落大小和年龄，几乎是未知的。在这项研究中，不同规模分类的野生菌落和已知年龄的菌落菌属Favites abdita的已知菌落（即从幼体到成年的性培养和饲养的菌落）在有性生殖开始时检查是否存在成熟的卵母细胞以确定大小和年龄。还确定了不同规模的野生菌落在生殖成熟开始时的繁殖力。根据最大菌落直径（A = 0.1-4.0 cm，B = 4.1-8.0 cm，C => 8.1 cm），将被调查和采样的菌落分为三个大小类别。对于野生和有性繁殖的菌落，包含配子的最小菌落的直径为1.8厘米，这表明这是性成熟开始时的最小菌落大小。与B和C类菌落相比，A类菌落的每个息肉平均卵母细胞计数较低（44±6.08；平均值±SE）（分别为469±62.41、278±57.15）。但是，A类菌落的平均卵母细胞几何平均直径更大（340.38±7。比B和C级分别为68μm和283.96±6.94μm，317.57±9.18μm）。这项研究的结果使珊瑚幼虫的直径小于等于4.0厘米的菌落的广泛使用的操作定义受到质疑，并且表明即使很小的菌落也可能对珊瑚礁的天然幼体池起着比以前认为的作用。