AGE AND SURVIVORSHIP OF DIAPAUSING EGGS IN A SEDIMENT EGG BANK
AGE AND SURVIVORSHIP OF DIAPAUSING EGGS IN A SEDIMENT EGG BANK
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DOI：
10.2307/1940704
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发表时间：
1995-09-01
期刊：
影响因子：
4.8
通讯作者：
ENGSTROM, DR
中科院分区：
文献类型：
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作者：
HAIRSTON, NG;VANBRUNT, RA;ENGSTROM, DR
我们在罗德岛两个小的淡水湖泊沉积物中测定了血足桡足动物滞育卵的密度。每隔1厘米切片的沉积物岩心显示，在沉积物表面附近，卵密度在4 × 10(4)到8 × 10(4)个/m(2)之间，在10-15厘米的深度处，两个湖泊的卵密度都下降到非常低的值，尽管在一个湖泊的沉积物中发现了30厘米深的卵。这些卵中有10%到50%是在短期的实验室实验中孵化出来的，而实际的卵存活率可能更高。pb -210年代测定显示，两个湖泊的沉积速率相对恒定，我们利用这一信息来估计鸡蛋的年龄。在一个湖,diapausing-egg的平均年龄为70.4岁(年龄中位数= 45.9年)和蛋孵出我们的最大年龄是332年。另一个湖,鸡蛋的平均年龄为48.9岁(年龄中位数= 35.9年)和蛋孵出我们的最大年龄是112年。我们计算蛋死亡率的回归(鸡蛋密度)沉积物的年龄的鸡蛋被送往获得估计死亡率1.5%和1.1 /年的两个湖泊。浮游动物的滞育卵代表了一种寿命较短的生物的寿命较长的生命史阶段。它们提供了世代重叠，这对生态和进化动力学都具有重大意义。
We determined the densities of diapausing eggs of the copepod Diaptomus sanguineus in sediments from two small freshwater lakes in Rhode Island. Sediment cores, sliced at 1-cm intervals, showed that egg densities ranged between 4 x 10(4) and 8 X 10(4) eggs/m(2) near the sediment surface and declined to very low values at depths of 10-15 cm in both lakes, although eggs were found as deep as 30 cm in the sediment of one lake. Between 10 and 50% of these eggs hatched in short-term laboratory experiments, and actual egg viability is probably higher. Pb-210-dating revealed relatively constant sedimentation rates in both lakes, and we use this information to estimate egg ages. In one lake, the mean diapausing-egg age is 70.4 yr (median age = 45.9 yr) and the maximum age of eggs we hatched was 332 yr. In the other lake, the mean egg age is 48.9 yr (median age = 35.9 yr) and the maximum age of eggs we hatched was 112 yr. We calculated egg mortality rates by regressing In(egg density) on the age of the sediment from which the eggs were taken to obtain estimates of 1.1 and 1.5% mortality/yr for the two lakes. Diapausing eggs of zooplankton represent a long-lived life history stage of an otherwise short-lived organism. They provide generation overlap that can have substantial significance for both ecological and evolutionary dynamics.