Olabarria C, Underwood A, Chapman M
Centre for Research on Ecological Impacts of Coastal Cities, Marine Ecology Laboratories A11 University of Sydney, NSW 2006, Australia.
Oecologia. 2002 Jul;132(2):159-166. doi: 10.1007/s00442-002-0940-6. Epub 2002 Jul 1.
The intertidal microgastropods Eatoniella atropurpurea, Amphithalamus incidata and Eatonina rubrilabiata are principally found at mid- to low-shore levels in coralline turf and in patches of sediment close to algal turf on rocky shores. All three species are more abundant in coralline turf (i.e. algal beds composed primarily of Corallina officinalis Linnaeus, often containing patches of sediment) than in sediment, although the latter two are also quite abundant in patches of sediment. Eatoniella atropurpurea seem to live on branches of coralline algae, whereas Eatonina rubrilabiata and A. incidata seem to inhabit the sediment. In this study, we investigated whether or not behaviour of these animals accounts for the patterns observed in the field. Particularly, this study deals with choices amongst three microhabitats (coralline algae, coralline algae plus sediment and sediment) by these three species of microgastropods. Laboratory experiments were designed to examine preferences. The designs of such experiments are complex because demonstrating preference necessitates demonstrating different behaviour when confronted with choices from that showed when no choice is available. This study describes an appropriate series of hypotheses about preferences and experimental designs to test them. Preferences were indicated by differences in occupancy of the microhabitats when presented with a mixture and when each type is presented alone. In such experiments, snails did show preferences, except for A. incidata which did not show a pattern. Thus, the behaviour could, at least partially, account for the patterns of distribution in the field. The designs of experiments used here may be of value in other studies of preferences among habitats.
潮间带微型腹足类动物深紫伊顿螺、镶嵌安氏螺和红唇伊顿螺主要分布在岩岸的珊瑚藻草皮以及靠近藻类草皮的沉积物斑块中的中低潮位区域。这三个物种在珊瑚藻草皮（即主要由药用珊瑚藻构成的藻床，通常含有沉积物斑块）中的数量比在沉积物中更多，尽管后两者在沉积物斑块中也相当丰富。深紫伊顿螺似乎生活在珊瑚藻的分支上，而红唇伊顿螺和镶嵌安氏螺似乎栖息在沉积物中。在本研究中，我们调查了这些动物的行为是否能解释在野外观察到的分布模式。特别是，本研究探讨了这三种微型腹足类动物在三种微生境（珊瑚藻、珊瑚藻加沉积物和沉积物）之间的选择。设计了实验室实验来检验偏好。此类实验的设计很复杂，因为要证明偏好就必须证明在有选择时与无选择时所表现出的行为不同。本研究描述了一系列关于偏好的合适假设以及用于检验这些假设的实验设计。当同时呈现混合物和单独呈现每种类型时，微生境的占据差异表明了偏好。在这类实验中，蜗牛确实表现出了偏好，但镶嵌安氏螺除外，它没有表现出特定模式。因此，这种行为至少可以部分解释野外的分布模式。这里使用的实验设计可能对其他关于生境偏好的研究有价值。
