For species with geographically restricted distributions, the impacts of habitat loss and fragmentation on long-term persistence may be particularly pronounced. We examined the genetic structure of Panama City crayfish (PCC), Procambarus econfinae, whose historical distribution is limited to an area approximately 145 km2, largely within the limits of Panama City and eastern Bay County, Florida, USA. Currently, PCC occupy approximately twenty-eight percent of its historical range, with suitable habitat composed of fragmented patches in the highly urbanized western portion of the range and managed plantations in the more contiguous eastern portion of the range. We used 1,640 anonymous single nucleotide polymorphisms to evaluate the effects of anthropogenic habitat modification on the genetic diversity and population structure of 161 PCC sampled from across it known distribution. First, we examined the urban habitat patches in the west compared to less-developed habitat patches in the east. Second, we used Approximate Bayesian Computation to model inferences on the demographic history of eastern and western populations. We found anthropogenic habitat modifications explain the genetic structure of PCC range-wide. Clustering analyses revealed significant genetic structure between and within eastern and western regions. Estimates of divergence between east and west were consistent with urban growth in the mid-20th Century. PCC have low genetic diversity and high levels of inbreeding and relatedness, indicating populations are small and isolated. Our results suggest that PCC have been strongly affected by habitat loss and fragmentation and management strategies, including legal protection, translocations, or reintroductions, may be necessary to ensure long-term persistence.

中文翻译：

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巴拿马城小龙虾（Procambarus econfinae）的城市化和种群遗传结构

对于地理分布受限的物种，栖息地丧失和破碎化对长期持久性的影响可能特别明显。我们检查了巴拿马城小龙虾 (PCC) Procambarus econfinae 的遗传结构，其历史分布仅限于大约 145 平方公里的区域，主要在巴拿马城和美国佛罗里达州东部湾县的范围内。目前，PCC 约占其历史范围的 28%，合适的栖息地由该地区高度城市化的西部的碎片斑块组成，以及该地区更连续的东部地区的人工种植园。我们使用了 1, 640 个匿名单核苷酸多态性，以评估人为栖息地改变对从已知分布中采样的 161 个 PCC 的遗传多样性和种群结构的影响。首先，与东部欠发达的栖息地斑块相比，我们检查了西部的城市栖息地斑块。其次，我们使用近似贝叶斯计算来模拟对东西方人口的人口统计历史的推断。我们发现人为栖息地的改变解释了 PCC 范围内的遗传结构。聚类分析揭示了东部和西部地区之间和内部的显着遗传结构。东西方差异的估计与 20 世纪中叶的城市增长一致。PCC 具有低遗传多样性和高水平的近亲繁殖和亲缘关系，表明种群小且孤立。我们的研究结果表明，PCC 受到栖息地丧失和破碎化的强烈影响，而管理策略，包括法律保护、易地或重新引入，可能是确保长期持久性所必需的。