Larval Settlement and Juvenile Mortality in a Recruitment‐Limited Coral Reef Fish Population
Larval Settlement and Juvenile Mortality in a Recruitment‐Limited Coral Reef Fish Population
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招募有限的珊瑚礁鱼群中的幼虫定居和幼鱼死亡率
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发表时间：
1986
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通讯作者：
B. Victor
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作者：
B. Victor
在巴拿马的圣布拉斯群岛，记录了蓝头濑鱼，塔拉斯-索马bifasciatum，幼虫定居的时间和空间格局。每日人口普查表明，幼虫在珊瑚礁上定居的时间很短，往往发生在新月前后，每年8月至12月之间达到高峰。每天的定居量与当地人口规模的变化无关，但被发现与珊瑚礁上沃茨的浮游珊瑚礁鱼幼虫的夜间捕获量显着相关。在三个尺度上研究了定居点的空间格局。在一个大的地理范围内，1000平方公里内有24个珊瑚礁，沉降强度存在巨大的变化，从一年到下一年非常一致。补充密度的最佳相关性是暴露于向岸流。这表明某些大尺度的海洋学过程决定了蓝头鱼在此尺度上的沉降强度。这些礁上的成虫密度直接反映了新兵的密度。每日耳石增量的计数表明，那些幼虫定居在低密度的珊瑚礁随后增长显着更快。在一个中间规模，1平方公里内的网站，有没有一致性的网站或月之间的沉降强度，这表明在此规模上的沉降强度的方差可能是随机过程的产物。在最小的尺度上，栖息地选择在一个补丁珊瑚礁，它被发现，新兵有不同的偏好，在他们选择的定居点。每日死亡率的蓝头鱼的时间表表明，死亡率是非常高的前3天的礁。少年死亡率，此外，被认为是独立的密度。因此，蓝头鱼的幼虫定居的模式坚持到成年人口相对不变。因此，建议在这一地区的蓝头鱼的分布和丰富的外部过程控制幼虫定居比任何生物相互作用的珊瑚礁组合内的产品。
The temporal and spatial patterns of larval settlement of the-bluehead wrasse, Thalas- soma bifasciatum, were documented in the San Blas Islands of Panama. Daily censuses indicated that larvae settle onto coral reefs in brief episodes that tended to occur around the new moon and peak in intensity between August and December of each year. The magnitude of settlement each day was unrelated to changes in the local population size but was found to be significantly correlated with the nightly catch of planktonic reef fish larvae in the waters over the reef. The spatial pattern of settlement was examined on three scales. On a large geographic scale, 24 reefs within 1000 km2, there was tremendous variability in settlement intensity that was very consistent from one year to the next. The best correlate of recruit density was exposure to the onshore current. It is suggested that some large- scale oceanographic process determines the intensity of settlement of bluehead wrasses on this scale. The densities of adults on these reefs directly reflected the densities of recruits. Counts of daily otolith increments indicated that those larvae that settled onto low-density reefs subsequently grew signifi- cantly faster. On an intermediate scale, sites within 1 km2, there was no consistency among sites or months in settlement intensity, suggesting that variance in settlement intensity on this scale may be the product of random processes. On the smallest scale, habitat selection within a patch reef, it was found that recruits had distinct preferences in their choices of settlement sites. The daily mortality schedule of bluehead wrasses indicated that mortality was extremely high for the first 3 d on the reef. Juvenile mortality was, furthermore, found to be independent of density. As a result, the patterns of larval settlement of bluehead wrasses persisted into the adult population relatively unchanged. It is therefore proposed that the distribution and abundance of bluehead wrasses in this region are more a product of the external processes controlling larval settlement than of any biological interactions within the reef assemblage.