Symbiosis regulation in a facultatively symbiotic temperate coral: zooxanthellae division and expulsion
Symbiosis regulation in a facultatively symbiotic temperate coral: zooxanthellae division and expulsion
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DOI：
10.1007/s00338-008-0363-x
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发表时间：
2008-09-01
期刊：
影响因子：
3.5
通讯作者：
Carrington, E.
中科院分区：
文献类型：
--
作者：
Dimond, J.;Carrington, E.
在美国南部新英格兰海岸的冬、夏两季，测定了共生性石蟹类的虫黄藻有丝分裂指数（MI）和排出率。虽然MI在夏季明显高于冬季，但季节间的平均驱逐率相当。因此，珊瑚似乎允许共生体密度的增加时，共生是有利的，在温暖的季节，然后在寒冷的季节，当虫黄藻可能会从珊瑚中汲取资源的净减少。鉴于以前的报道，光合作用在A。poculata共生体不发生低于约6摄氏度，相当大的虫黄藻分裂在3摄氏度和黑暗中表明，虫黄藻是异养在低季节性温度。最后，检查驱逐作为一个函数的zooxanthropium密度发现，珊瑚与zooxanthropium密度非常低的出口显着更大的比例，他们的共生体，显然让他们坚持在一个稳定的azooxanthellate状态。
Zooxanthellae mitotic index (MI) and expulsion rates were measured in the facultatively symbiotic scleractinian Astrangia poculata during winter and summer off the southern New England coast, USA. While MI was significantly higher in summer than in winter, mean expulsion rates were comparable between seasons. Corals therefore appear to allow increases in symbiont density when symbiosis is advantageous during the warm season, followed by a net reduction during the cold season when zooxanthellae may draw resources from the coral. Given previous reports that photosynthesis in A. poculata symbionts does not occur below approximately 6 degrees C, considerable zooxanthellae division at 3 degrees C and in darkness suggests that zooxanthellae are heterotrophic at low seasonal temperatures. Finally, examination of expulsion as a function of zooxanthellae density revealed that corals with very low zooxanthellae densities export a significantly greater proportion of their symbionts, apparently allowing them to persist in a stable azooxanthellate state.