Pearse Vicki Buchsbaum
Biol Bull. 1974 Dec;147(3):641-651. doi: 10.2307/1540747.
The pattern of expansion and contraction by the sea anemone Anthopleura elegantissima differs in individuals with or without endosymbiotic zooxanthellae. Anemones without zooxanthellae, found in dark habitats, do not regularly expand or contract under changes in light. Anemones with zooxanthellae expand in moderate light and contract in intense light or in darkness, with striking uniformity. However, this behavior does not always depend directly on the presence of zooxanthellae. Anemones that have previously had endosymbiotic zooxanthellae subsequently expand and contract with changes in light in the absence of these algae. Thus, conditioned responses may be involved. It is suggested that expansion and contraction of the anemones may play an important role in favorably regulating the amount of light to which their zooxanthellae are exposed.
优雅海葵（Anthopleura elegantissima）的扩张和收缩模式在有无内共生虫黄藻的个体之间存在差异。在黑暗栖息地发现的没有虫黄藻的海葵，在光照变化时不会定期扩张或收缩。有虫黄藻的海葵在适度光照下扩张，在强光或黑暗中收缩，具有惊人的一致性。然而，这种行为并不总是直接取决于虫黄藻的存在。先前有内共生虫黄藻的海葵在没有这些藻类的情况下，随后会随着光照变化而扩张和收缩。因此，可能涉及条件反应。有人认为，海葵的扩张和收缩可能在有利调节其虫黄藻所暴露的光量方面发挥重要作用。
