Shick J M
Biol Bull. 1990 Aug;179(1):148-158. doi: 10.2307/1541749.
Depending on their size and morphology, anthozoan polyps and colonies may be diffusion-limited in their oxygen consumption, even under well-stirred, air-saturated conditions. This is indicated by an enhancement of oxygen consumption under steady-state hyperoxic conditions that simulate the levels of O2 produced photosynthetically by zooxanthellae in the hosts' tissues. Such hyperoxia in the tissues of zooxanthellate species negates the effect of the diffusive boundary layer, and increases the rate of oxygen consumption; thus, in many cases, the rate of respiration measured under normoxia in the dark may not be representative of the rate during the day when the zooxanthellae are photosynthesizing and when the supply of oxygen for respiration is in the tissues themselves, not from the environment. These results have implications in respirometric methodology and in calculating the rate of gross photosynthesis in energetic studies. The activity of cytochrome c oxidase is higher in aposymbiotic than in zooxanthellate specimens of the sea anemone Aiptasia pulchella, and this may indicate a compensation for the relative hypoxia in the tissues of the former, enhancing the delivery of oxygen to the mitochondria from the environment.
根据其大小和形态，即使在充分搅拌、空气饱和的条件下，珊瑚虫和群体的氧气消耗可能受扩散限制。这一点通过稳态高氧条件下氧气消耗的增强得以体现，该条件模拟了虫黄藻在宿主组织中光合作用产生的氧气水平。虫黄藻共生物种组织中的这种高氧消除了扩散边界层的影响，并提高了氧气消耗速率；因此，在许多情况下，在黑暗中常氧条件下测得的呼吸速率可能无法代表虫黄藻进行光合作用且呼吸所需氧气由组织自身而非环境提供时的白天速率。这些结果对呼吸测量方法以及能量研究中总光合作用速率的计算具有启示意义。在海葵美丽艾氏海葵的无共生体标本中，细胞色素c氧化酶的活性高于有虫黄藻共生的标本，这可能表明对前者组织中相对缺氧的一种补偿，增强了从环境向线粒体的氧气输送。
