Parasitism, movement, and distribution of the snail Diloma subrostrata (Trochidae) in a soft-sediment intertidal zone
Parasitism, movement, and distribution of the snail Diloma subrostrata (Trochidae) in a soft-sediment intertidal zone
复制标题
软沉积物潮间带蜗牛 Diloma subrostrata (Trochidae) 的寄生、运动和分布
DOI：
10.1139/z01-167
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发表时间：
2001
影响因子：
1.4
通讯作者：
R. Poulin
中科院分区：
文献类型：
--
作者：
Aroha A. Miller;R. Poulin
尽管报道了它们对宿主生殖、生长、生存和栖息地利用的影响，但寄生虫在决定群落结构中的作用仍然知之甚少。吸虫感染的蜗牛是一个普遍存在的特点，潮间带系统在世界各地。在这项研究中，吸虫寄生虫的运动和扩散的蜗牛Diloma subrostrata软沉积物海岸的影响进行了研究，使用标记-再捕获实验。螺的自然密度和壳宽在潮间带的上部和下部之间达到峰值;在该区域内释放了显著的螺。寄生蜗牛往往有较大的壳比nonparasitized同种，较大的蜗牛往往比较小的蜗牛在24小时后，他们的标记和释放移动更大的线性距离。壳宽校正后，被寄生的蜗牛被发现移动一个显着较短的距离比nonparasitized蜗牛。此外，寄生蜗牛选择的平均方向几乎是平行于水的边缘，而nonparasitized蜗牛采取的几乎是直接朝向潮间带的上部。虽然两种蜗牛的平均方向有统计学差异，但个体蜗牛的方向分布相当分散，这一结果的生物学意义令人怀疑。如果不详细了解寄生虫的整个生命周期，就很难确定这种在传播方向上的小偏差是否是寄生吸虫对蜗牛行为的适应性操纵。尽管如此，这些结果表明，吸虫限制了寄生D的运动范围，并可能限制了运动方向。因此，可以有助于蜗牛种群的空间结构。
Despite reports of their effects on host reproduction, growth, survival, and habitat use, the role of parasites in determining community structure is still poorly understood. Trematode infections in snails are a ubiquitous feature of intertidal systems worldwide. In this study, the influence of a trematode parasite on the movement and dispersal of the trochid snail Diloma subrostrata on a soft-sediment shore is examined using mark-recapture experiments. The natu- ral densities and shell widths of the snail peak between the upper and lower portions of the intertidal zone; marked snails were released within this area. Parasitized snails tended to have larger shells than nonparasitized conspecifics, and larger snails tended to move a greater linear distance than smaller snails in the 24 h following their marking and release. After shell width was corrected for, parasitized snails were found to move a significantly shorter distance than nonparasitized snails. In addition, the mean direction chosen by parasitized snails was almost parallel to the water's edge, whereas that taken by nonparasitized snails was almost directly toward the upper portion of the intertidal zone. Although the mean directions taken by the two types of snails were statistically different, the considerable scatter in the distributions of directions taken by individual snails casts a doubt over the biological significance of the result. Without detailed knowledge of the parasite's full life cycle it is difficult to determine whether this small bias in the direction of dispersal is an adaptive manipulation of snail behaviour by the parasitic trematode. Nevertheless, these results show that the trematode limits the range of movement, and possibly the direction of movement, of parasitized D. subrostrata, and can therefore contribute to the spatial structuring of the snail population.