Naaykens Taylor, D'Aloia Cassidy C
Department of Biological Sciences, University of New Brunswick - Saint John, Saint John, New Brunswick, Canada.
Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada.
Mol Ecol. 2022 Jun;31(11):3072-3082. doi: 10.1111/mec.16465. Epub 2022 Apr 22.
Larval exchange among marine populations is a vital driver of population dynamics and has the potential to inform conservation actions, but accurately measuring dispersal remains challenging. Consequently, empirical dispersal kernels have been measured for only a few marine species. Here, we obtained indirect dispersal estimates using an isolation-by-distance (IBD) model in the coral reef fish Elacatinus lori and assessed the accuracy of these estimates by comparing them to direct measurements of dispersal from genetic parentage analysis. Specifically, drawing on the IBD slope and effective population density, we indirectly estimated sigma (σ), the spread of a dispersal distribution. While the spread of the directly measured distribution was σ = 3.93 km (95% CI: 3.29-4.71 km), the spread of the IBD distribution was σ = 4.10 km (95% CI: 3.23-5.03) and σ = 2.90 km (95% CI: 2.26-3.59), assuming a random or monogamous mating system, respectively. Parameterizing Laplace dispersal kernels with these values of σ yielded patterns that were remarkably similar to a kernel fit to the direct parentage data. We also found that, like many marine fishes, E. lori has a large effective population size. However, uncertainty in effective size did not ultimately have a strong effect on the IBD-based dispersal estimates. Taken together, these findings illustrate that accurate dispersal estimates can be produced by indirect IBD methods and suggest that this more feasible approach to estimating dispersal may be broadly applicable to the study of marine larval dispersal.
海洋种群间的幼体交换是种群动态的一个重要驱动因素，并且有可能为保护行动提供依据，但准确测量扩散仍然具有挑战性。因此，仅对少数海洋物种测量了实证扩散核。在这里，我们使用距离隔离（IBD）模型获得了珊瑚礁鱼类洛氏艾氏鱼的间接扩散估计值，并通过将这些估计值与基于遗传亲权分析的直接扩散测量值进行比较，评估了这些估计值的准确性。具体而言，利用IBD斜率和有效种群密度，我们间接估计了扩散分布的扩散范围σ。虽然直接测量的分布扩散范围为σ = 3.93千米（95%置信区间：3.29 - 4.71千米），但假设分别为随机或一夫一妻制交配系统时，IBD分布的扩散范围分别为σ = 4.10千米（95%置信区间：3.23 - 5.03）和σ = 2.90千米（95%置信区间：2.26 - 3.59）。用这些σ值对拉普拉斯扩散核进行参数化，得到的模式与拟合直接亲权数据的核非常相似。我们还发现，与许多海洋鱼类一样，洛氏艾氏鱼具有较大的有效种群规模。然而，有效规模的不确定性最终对基于IBD的扩散估计并没有强烈影响。综上所述，这些发现表明，可以通过间接IBD方法产生准确的扩散估计值，并表明这种更可行的扩散估计方法可能广泛适用于海洋幼体扩散研究。
