Vetigastropod phylogeny and a new concept of Seguenzioidea: independent evolution of copulatory organs in the deep‐sea habitats
Vetigastropod phylogeny and a new concept of Seguenzioidea: independent evolution of copulatory organs in the deep‐sea habitats
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DOI：
10.1111/j.1463-6409.2007.00316.x
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发表时间：
2007-12
影响因子：
2.5
通讯作者：
Y. Kano
中科院分区：
文献类型：
--
作者：
Y. Kano
通过对一个线粒体（细胞色素氧化酶I，COI）和两个核（组蛋白H3和18S rRNA）基因序列的单独和组合分析，重建了Vetigastropoda（软体动物：腹足纲）的贝叶斯和最大似然遗传学，重点是密集的分类学采样。隶属于13科25亚科的70余种Vetigastropod构成了一个相对于Neomphalina和Cocculinoidea两个外类群的强大分支。在遗传学上有争议的Seguenziidae科似乎是一个衍生的Vetigastropoda，并与Eucycline和cataegine trochids以及三个skeneimorphs（Adeuomphalus，Ventsia和Xyloskenea）构成了一个高度支持的分支。这些分类群在此被视为Seguenzioidea总科，在形态上非常多样，仅通过壳、齿舌和头足特征的合模性组合进行分组。Seguenziidae的解剖学特征，包括阴茎和贮精囊的存在，都是独立于高等腹足类分支的无定形条件，这是由于体积小和对深海栖息地的反应，其中精子储存似乎特别有益于个体的低数量密度和有限的配子发生周期性线索。事实上，内部或半内部受精在Vetiastropoda中至少进化了六次，基本上是在深海谱系中，具有弱的系统发育限制。其他具有高支持值的新的矢腹足类分支包括：Turbinidae + Tegulinae（Trochidae）+ Skeneidae s.s.，Clypeosectidae + Lepetodrilidae，Anatominae（Scissurellidae）+ Bathyxylophila（Skeneidae）和Lepetodriloidea + Scissurellidae +Bathyxylophila。
Bayesian and maximum‐likelihood phylogenies of Vetigastropoda (Mollusca: Gastropoda) were reconstructed by separate and combined analyses of one mitochondrial (cytochrome oxidase I, COI) and two nuclear (histone H3 and 18S rRNA) gene sequences, with an emphasis on dense taxonomic sampling. More than 70 vetigastropod species belonging to 13 families and 25 subfamilies constituted a robust clade against the two outgroup clades Neomphalina and Cocculinoidea. The phylogenetically controversial family Seguenziidae appeared as a derived Vetigastropoda and constituted a highly supported clade with eucycline and cataegine trochids, and three skeneimorphs (Adeuomphalus, Ventsia and Xyloskenea). These taxa herein treated as the superfamily Seguenzioidea are morphologically very diverse and grouped only by the combination of symplesiomorphies in the shell, radular and head‐foot characters. Anatomical peculiarities of Seguenziidae, including the presence of the penis and seminal receptacle, are all apomorphic conditions independently derived from those in higher gastropod clades, as a consequence of the small size and in response to deep‐sea habitats, where sperm storage seems to be especially beneficial with low numerical density of individuals and limited periodic cues for gametogenesis. Indeed, internal or semi‐internal fertilization has been evolved at least six times in Vetigastropoda, essentially in deep‐sea lineages, with weak phylogenetic constraints. Other new vetigastropod clades with high support values include: Turbinidae + Tegulinae (Trochidae) + Skeneidae s.s., Clypeosectidae + Lepetodrilidae, Anatominae (Scissurellidae) + Bathyxylophila (Skeneidae) and Lepetodriloidea + Scissurellidae +Bathyxylophila.