Spatial distribution and morphological responses to predation in the salt marsh periwinkle
Spatial distribution and morphological responses to predation in the salt marsh periwinkle
复制标题
盐沼长春花的空间分布和形态对捕食的响应
作者：
A. J. Rietl;M. G. Sorrentino;B. J. Roberts
盐沼长春花（学名：Littoraria pillorata）是一种常见的软体动物，生活在美国海湾和大西洋沿岸的沼泽地。一些研究集中在长春花对互花米草生产的影响和石油对长春花生存能力的影响，但蜗牛的一般生态学一直报道不足。在这项研究中，我们测量了L的空间分布、生物量、壳修复频率和一系列形态特征。在横跨阿查法拉亚河和密西西比河之间的路易斯安那州东南海岸的五个地区中，每个地区都有三个地点的阿科拉塔。采样沿着50 m的边缘到内部样带在S。以互花米草为主的沼泽。我们发现L.不同地区的珊瑚密度、个体生物量和总面积生物量差异显著。每一个也显着不同的距离，从沼泽边缘，总长春花面积生物量除外。我们看到了一个总的趋势，在大多数地区，长春花密度往往是最大的10米的沼泽边缘和生物量往往是最大的20-30米的沼泽边缘，但是，无论是长春花密度和生物量是与S。互花米草密度或茎高。壳长和生物量之间的异速生长关系在所有区域之间变化显著，表明该物种具有不同的区域生长模式。异速生长这些区域模式的一个可能的驱动程序是捕食压力的差异，增加捕食惊吓在港口Fourchon网站对应的蜗牛与较大的外壳，但更少的内部生物量单位长度相比，其他地区。本研究首次对盐沼长春花的空间生态学和区域形态学进行了大尺度描述，并提出了L.在其他研究中发现的植物产量的变化可能因地理和空间位置而异
The salt marsh periwinkle (Littoraria irrorata) is a common and often abundant mollusk in marshes of the Gulf and Atlantic coasts of the United States. Several studies have focused on the effects of periwinkles on Spartina alterniflora production and the effects of oil on periwinkle survivability, yet the general ecology of the snail has been underreported. In this study, we measured spatial distributions, biomass, shell repair frequency, and a suite of morphological characteristics of L. irrorata at three sites in each of five regions spanning the southeastern Louisiana Coast between the Atchafalaya and Mississippi rivers. Sampling was conducted along 50 m edge-to-interior transects in S. alterniflora-dominated marshes. We found that L. irrorata density, individual biomass, and total areal biomass significantly varied by region. Each also significantly varied with distance from the marsh edge, with the exception of total periwinkle areal biomass. We saw a general trend across most regions where periwinkle density tended to be greatest 10 m from the marsh edge and biomass tended to be greatest 20–30 m from the marsh edge; however, neither periwinkle density nor biomass was related to S. alterniflora density or stem height. The allometric relationship between shell length and biomass varied significantly between all regions, indicating that this species has differing regional growth patterns. A possible driver of these regional patterns in allometry is differences in predation pressures, with increased predation scaring at Port Fourchon sites corresponding to snails with larger shells yet less internal biomass per length compared to other regions. This study provides the first large-scale description of the spatial ecology and regional morphometry of the salt marsh periwinkle, an important organism in structuring salt marsh ecosystems, and suggests that the pressures exerted by L. irrorata on plant production found in other studies likely varies by geography and spatial location