Comparison of morphological and molecular traits for species identification and taxonomic grouping of oncaeid copepods
Comparison of morphological and molecular traits for species identification and taxonomic grouping of oncaeid copepods
复制标题
DOI：
10.1007/s10750-010-0094-1
复制
发表时间：
2011-05-01
期刊：
影响因子：
2.6
通讯作者：
Machida, Ryuji J.
中科院分区：
文献类型：
--
作者：
Boettger-Schnack, Ruth;Machida, Ryuji J.
远洋海洋桡足类Oncaeidae家族是高度多样化的（全世界超过100种），包括大量的兄弟物种，这是很难识别的形态，因为他们非常小的尺寸（0.18-1.2毫米的成年人总长度）。全球调查的oncaeid生物多样性严重阻碍了不足的分类知识，特别是物种已首次被描述从欧洲地中海（模式产地）。据报道，其中许多物种是非常遥远的海洋区域小型桡足类群落的关键类群。然而，由于分类学上的不确定性，不能排除这些所谓的世界性物种中至少有一些实际上代表了一个不同但密切相关的物种的复合体。为了提高鉴别地中海起源的Oncaeidae的基础，在本研究中应用了新的诊断特征与传统方法相结合。在地中海的东西向横断面上，用0.1毫米网眼大小的细网对桡足类进行采样，最大深度为1，000 m。Oncaeid物种和形式的变体是预定义的形态和形态种的遗传身份进行了分析，约650和500 bp的线粒体COI和12 S srRNA基因序列的区域，分别（条形码）。成功分析了来自24种和形式的67个个体，其中包括12种和一种地中海起源的形式。对于Oncaeidae，12 S扩增被证明是更成功的（23种）比COI扩增（13种和1型）。结合形态学和分子生物学研究结果，讨论了三个方面的问题：（1）三个Triconia种的遗传差异的确认，它们通过形态学特征被解释为兄弟种;（2）Oncaeids卵圆复合体内种的遗传距离;（3）Oncaeamidiocleea（Claus）两种变型的分类地位。
The pelagic marine copepod family Oncaeidae is highly diversified (over 100 species worldwide) and includes a great number of sibling species, which are difficult to identify morphologically, because of their very small size (0.18-1.2 mm total length as adults). Global investigations of oncaeid biodiversity are severely hampered by insufficient taxonomic knowledge, in particular for species which have first been described from the European Mediterranean Sea (type locality). Many of these species have been reported as key taxa of small-sized copepod communities in very distant oceanic regions. However, due to the taxonomic uncertainties it cannot be excluded that at least some of these allegedly cosmopolitan species in reality represent a complex of distinct, yet closely related, species. To improve the basis for the identification of Oncaeidae of Mediterranean origin, new diagnostic characters in combination with traditional methods were applied in the present study. Copepods were sampled with fine nets of 0.1 mm mesh size down to a maximum depth of 1,000 m on a west-east-transect in the Mediterranean Sea. Oncaeid species and form variants were predefined morphologically and the genetic identity of the morphospecies was analysed by about 650 and 500 bp region of the mitochondrial COI and 12S srRNA gene sequence, respectively (barcoding). A total of 67 individuals from 24 oncaeid species and forms were successfully analysed, including 12 species and one form of Mediterranean origin. For Oncaeidae, the 12S amplification turned out to be more successful (23 species) than the COI amplification (13 species and 1 form). Together, the morphological and molecular results are discussed with respect to three topics: (1) confirmation of a genetic distinction of three Triconia species, which have been interpreted as sibling species by morphological characters, (2) genetic distance of species within the ovalis-complex of oncaeids and (3) the taxonomic status of two form variants of Oncaea mediterranea (Claus).