Diversity and geographic distribution of ciliates (Protista: Ciliophora)
Diversity and geographic distribution of ciliates (Protista: Ciliophora)
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DOI：
10.1007/s10531-007-9254-7
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发表时间：
2008-02-01
影响因子：
3.4
通讯作者：
Katz, Laura A.
中科院分区：
文献类型：
--
作者：
Foissner, Wilhelm;Chao, Anne;Katz, Laura A.
大约有 4,500 种自由生活的纤毛虫形态种已被描述，平均同义率为 20%。我们估计 83-89% 的纤毛虫多样性仍未被描述，使用以下概率：详细的栖息地研究表明所描述的形态种数量必须加倍：4,500 -> 9,000；由于具有相似的间期形态但不同的休眠包囊的物种，这一数字必须增加约 50%：9,000 -> 13,500；遗传和分子数据表明，这个值必须增加一倍或三倍：13,500 -> 27,000 至 40,000 个自由生活的生物纤毛虫物种。关于纤毛虫地理分布的知识在很大程度上取决于旗舰物种和统计分析，因为可靠的动物区系研究很少，而且分子数据仍处于起步阶段。我们提出了 52 种纤毛虫旗舰物种的清单作为可检验的假设，即，当在所有或大多数生物地理区域中发现相当数量的纤毛虫物种时，必须拒绝某些纤毛虫物种分布受限的假设。旗舰物种和统计分析一致显示冈瓦南和劳亚纤毛虫群落，表明盘古大陆的分裂深刻影响了纤毛虫的分布，而稀有物种在地理分化中发挥着关键作用。然而，也有大量证据表明自由生活的纤毛虫是大陆、区域和地方特有的。分子研究通常表明纤毛虫形态种具有高水平的遗传多样性，这表明许多纤毛虫物种的形态和分子进化可能是脱钩的。关于纤毛虫生物地理学的分子研究存在差异，可能是因为大多数研究仍然集中在单个分子标记上。总之，数据表明纤毛虫的生物地理学与植物和动物相似，但世界性的比例增加，有利于中度流行模型。
About 4,500 free-living ciliate morphospecies have been described, applying an average synonymy rate of 20%. We estimate that 83-89% of the ciliate diversity is still undescribed, using the following probabilities: detailed habitat studies suggest that the described number of morphospecies must be doubled: 4,500 -> 9,000; this figure has to be increased by about 50% due to species with similar interphase morphology but different resting cysts: 9,000 -> 13,500; the genetic and molecular data suggest that this value must be doubled or trebled: 13,500 -> 27,000 to 40,000 free-living, biological ciliate species. The knowledge on geographic distribution of ciliates heavily depends on flagship species and statistical analyses because reliable faunistic studies are rare and molecular data are still in its infancy. We present a list of 52 ciliate flagship species as a testable hypothesis, i.e., the hypothesis of restricted distribution of certain ciliate species must be refused when a considerable number of them is found in all or most biogeographic regions. Flagship species and statistical analyses consistently show Gondwanan and Laurasian ciliate communities, suggesting that the split of Pangaea deeply influenced ciliate distribution and rare species play a key role in geographic differentiation. However, there is also substantial evidence for continental, regional, and local endemism of free-living ciliates. The molecular studies usually show a high level of genetic diversity underlying ciliate morphospecies, suggesting that morphologic and molecular evolution may be decoupled in many ciliate species. Molecular studies on ciliate biogeography are at variance, possibly because most are still focusing on single molecular markers. In sum, the data indicate that ciliate biogeography is similar to that of plants and animals, but with an increased proportion of cosmopolites, favouring the moderate endemicity model.