Extant Ceratolithus cristatus life-cycle observations and taxonomic simplification.
Extant Ceratolithus cristatus life-cycle observations and taxonomic simplification.
复制标题
现存冠角角藻生命周期观察和分类学简化。
DOI：
--
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
J. Young
中科院分区：
文献类型：
--
作者：
O. Archontikis;J. Young
关于龟尾藻的分类和复杂的生活史模式，目前仍然知之甚少，在这种生活史中，异球藻的产生阶段与含角石的阶段有关。对马尔代夫地表水的浮游生物样本进行的研究发现，有几个含有球藻的标本和一些组合球藻，其中两个球石与三种形态不同的球石类型有关--马蹄形球藻、纤细的环状异球藻和圆形球石。在研究了这些样本中的大量陶瓷结石后，我们能够证明，克里斯塔和Telesmus陶瓷结石的形态是相互交织的，代表了一种生长顺序，而不是基因分化。基于这些观察和对其他证据的重新检验，我们提出了现代海洋中存在的两个种--C.criatus和C.nishidae n.comb。此外，我们的观察表明，在该物种的两个生活史阶段，环状球藻和平面球藻交织在一起，因此，异形球藻出现在两个生活史阶段。
There is still limited knowledge on the taxonomy and complex life-cycle pattern of Ceratolithus cris-tatus , in which the heterococcolith-producing phase is associated with a ceratolith-bearing phase. A study of plankton samples from the surface-waters of the Maldives revealed several C. cristatus ceratolith-bearing specimens and a number of combination coccospheres, two of which had an association of three morphologically-distinct coccolith types––horseshoe-shaped C. cristatus CER telesmus type ceratoliths, delicate, hoop-shaped heterococcoliths and circular C. cristatus HET coccolithomorpha type planoliths. Having studied a large number of ceratoliths from these samples, we were able to demonstrate that the cristatus and telesmus ceratolith morphotypes intergrade, representing a growth sequence rather than genotypic differentiation. Based on these observations and a re-examination of other evidence, we propose that two Ceratolithus species occur in the modern ocean–– C. cristatus and C. nishidae n. comb. In addition, our observations indicated that, in C. cristatus , the hoop-coccoliths and planoliths intergrade, and hetero-coccoliths, therefore, occur in two life-cycle phases of this species.