McDaniel Courtney Holt, McHugh Joseph V, Batzer Darold P
Springs Stewardship Institute, Museum of Northern Arizona, 3101 N. Fort Valley Rd, Flagstaff, AZ, 86001.
Department of Entomology, University of Georgia, 413 Biological Sciences Building, Athens, GA, 30602.
Environ Entomol. 2017 Jun 1;46(3):494-501. doi: 10.1093/ee/nvx063.
Coexistence of closely related species has long been a focus of biologists in their efforts to explain mechanisms that drive community assembly. Dytiscidae (predaceous diving beetles) are a group that shows a particularly high affinity for sympatry despite their relatedness. Our objective was to investigate the degree of overlap among Neoporus (Guignot) species (Coleoptera: Dytiscidae) in floodplains of the southeastern United States. We sampled two floodplain habitats (permanent oxbow lakes and temporarily flooded pools) of the Altamaha River (Georgia, USA) for Neoporus species over three years. Six species of Neoporus were collected during our study, and a significant amount of overlap (spatial and temporal) was documented. Analysis suggested that none of the species exhibited a preference toward one habitat type or the other. Temporally, no striking patterns of segregation emerged. No negative correlations between species were documented, but neither were significant positive correlations found. This absence of distinct patterns suggests a lack of segregation among Neoporus species in floodplains of the Altamaha River. While Dytiscidae in general appears to be a particularly sympatric group of organisms, overlap among congeneric species within the family has been documented less frequently. Our study provides new insight into the degree to which dytiscids are capable of coexisting in space and time.
近缘物种的共存长期以来一直是生物学家努力解释驱动群落组装机制的重点。龙虱科（肉食性潜水甲虫）是一个尽管存在亲缘关系但对同域分布表现出特别高亲和力的类群。我们的目标是调查美国东南部洪泛平原上新孔龙属（吉诺）物种（鞘翅目：龙虱科）之间的重叠程度。我们在三年时间里对美国佐治亚州阿尔塔马哈河的两个洪泛平原栖息地（永久性牛轭湖和临时被洪水淹没的水塘）进行采样，以获取新孔龙属物种。在我们的研究过程中收集到了六种新孔龙属物种，并记录到了大量的重叠（空间和时间上的）。分析表明，没有一个物种对一种或另一种栖息地类型表现出偏好。在时间上，没有出现明显的隔离模式。没有记录到物种之间的负相关，但也没有发现显著的正相关。这种缺乏明显模式的情况表明，在阿尔塔马哈河洪泛平原的新孔龙属物种之间不存在隔离。虽然一般来说龙虱科似乎是一个特别同域分布的生物类群，但该科内同属物种之间的重叠情况记录得较少。我们的研究为龙虱科在空间和时间上共存的程度提供了新的见解。
