Living males of the ‘ancient asexual’ Darwinulidae (Ostracoda: Crustacea)
Living males of the ‘ancient asexual’ Darwinulidae (Ostracoda: Crustacea)
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DOI：
10.1098/rspb.2005.3452
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发表时间：
2006-06
期刊：
影响因子：
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通讯作者：
R. J. Smith;T. Kamiya;D. Horne
中科院分区：
文献类型：
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作者：
R. J. Smith;T. Kamiya;D. Horne
在日本屋久岛发现了三个新种-。这是100多年来第一份关于活达尔文雄性的报告，他们的形态对19世纪末的两个记录提出了质疑。雄性达尔文虫的存在也质疑了达尔文虫科是一个完全古老的无性繁殖群体的假设，无性繁殖超过2亿年。雄性甲壳的大小和形状与同一物种的A-1幼年雌性相似，这表明在其他活的和化石物种中，雄性可能被视为A-1幼年。触角和第五肢是两性异形的：雄性触角有六节，而雌性触角有五节，并且在额外的节边界处有一系列假定的化学受体，而雄性第五肢有发达的抓钩，就像许多介形类的雄性一样。缺乏Zenker的器官和复杂的内部结构内的半阴茎矛盾以前的假设的系统发育位置的达尔文。
Three living male darwinulid ostracods of a new species of the genus Vestalenula have been found in Yakushima, Japan. This is the first report of living darwinulid males for over 100 years and their morphology casts doubt on the two previous records from the late 1800s. The presence of male darwinulids also calls into question the hypothesis that the family Darwinulidae is an exclusively ancient asexual group, reproducing without sex for over 200 million years (Myr). Male carapaces are of similar size and shape to A-1 juvenile females of the same species, suggesting that males may have been dismissed as A-1 juveniles in other living and fossil species. The antennae and fifth limbs are sexually dimorphic: the male antennae have six segments compared with five in the female and a series of putative chemical receptors originating at the extra segment boundary, while the male fifth limbs have well-developed grasping hooks, as in males of many ostracod groups. The lack of Zenker's Organ and of complex internal structures within the hemipenis contradicts previous hypotheses of the phylogenetic position of darwinulids.