ASPECTS OF THE FERTILIZATION ECOLOGY OF BROADCAST SPAWNING CORALS - SPERM DILUTION EFFECTS AND INSITU MEASUREMENTS OF FERTILIZATION
ASPECTS OF THE FERTILIZATION ECOLOGY OF BROADCAST SPAWNING CORALS - SPERM DILUTION EFFECTS AND INSITU MEASUREMENTS OF FERTILIZATION
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DOI：
10.2307/1542017
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发表时间：
1992-12-01
影响因子：
1.6
通讯作者：
BABCOCK, R
中科院分区：
文献类型：
--
作者：
OLIVER, J;BABCOCK, R
通过一系列的实验室和野外试验，研究了配子稀释对三种珊瑚受精率的影响。配子在产卵后2小时仍能存活，但有一个物种在产卵后3-4小时表现出生育力下降的迹象。在实验室进行的精子稀释试验表明，受精在精子浓度为每毫升10（5）-10（6）时达到最大值，在较高和较低浓度下都会出现受精减少。通过将卵子暴露于在珊瑚产卵后不同时间和地点从野外采集的水样中，可以估计野外的“受精潜力”。这一抽样方案表明，在只有少量珊瑚产卵的夜晚（小产卵），受精潜力远低于主要产卵的夜晚。在主要的产卵夜，受精潜力一直高产卵后，但此后成为空间变量。受精卵和胚胎的实地收集的样本产卵后的百分比也较高，在主要产卵的夜晚比在未成年人产卵nights.These测量表明，配子稀释可以发挥重要作用，限制珊瑚卵受精在该领域在自然产卵。因此，珊瑚在相当大的选择压力下同步产卵，以便在水柱中产生高浓度的配子，从而最大限度地提高成功受精的可能性。除了同步产卵外，珊瑚还通过产卵在海面上积聚的漂浮配子束，以及在低水位运动期间产卵，尽量减少配子稀释的影响。
A series of laboratory and field experiments was carried out to determine the effects of gamete dilution on fertilization rates in three species of reef coral. Gametes remained viable for 2 h after spawning, but one species exhibited signs of reduced fertility 3-4 h after spawning. Sperm dilution trials carried out in the laboratory indicated that fertilization reaches a maximum at sperm concentrations of 10(5)-10(6) per ml, with reduced fertilization occurring at both higher and lower concentrations.Estimates of ''fertilization potential'' in the field were obtained by exposing eggs to water samples taken from the field at various times and locations following episodes of coral spawning. This sampling program indicated that on nights when only small numbers of coral spawned (minor spawning), the fertilization potential was much lower than on major spawning nights. On major spawning nights, fertilization potential was consistently high just after spawning, but became spatially variable thereafter. The percentage of fertilization in field-collected samples of eggs and embryos just after spawning was also higher during major spawning nights than during minor spawning nights.These measurements indicate that gamete dilution can play an important role in limiting the fertilization of coral eggs in the field during natural spawnings. It follows, therefore that corals are under considerable selective pressure to spawn synchronously in order to generate high gamete concentrations in the water column and thus to maximize the probability of successful fertilization. In addition to spawning in synchrony, corals also minimize the effects of gamete dilution by spawning buoyant gamete bundles that accumulate at the sea surface, and by spawning during periods of low water motion.