MICROANATOMY, SHELL STRUCTRE AND MOLECULAR PHYLOGENY OF LEPTOGYRA, XYLEPTOGYRA AND LEPTOGYROPSIS (GASTROPODA: NEOMPHALIDA: MELANODRYMIIDAE) FROM SUNKEN WOOD
MICROANATOMY, SHELL STRUCTRE AND MOLECULAR PHYLOGENY OF LEPTOGYRA, XYLEPTOGYRA AND LEPTOGYROPSIS (GASTROPODA: NEOMPHALIDA: MELANODRYMIIDAE) FROM SUNKEN WOOD
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DOI：
10.1093/mollus/eyn030
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发表时间：
2008-11-01
影响因子：
1.2
通讯作者：
Haszprunar, Gerhard
中科院分区：
文献类型：
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作者：
Hess, Martin;Beck, Friederike;Haszprunar, Gerhard
来自新西兰近海深处沉没木头的螺旋状微腹足动物属细旋体、木旋体和细旋体最初根据贝壳特征、外部形态和齿舌的精细结构被归类为定义不明确的石腹足纲（Vetigastropoda，Trochoidea）。我们通过连续半薄切片和计算机辅助 3D 重建，研究了几个代表的显微解剖学和组织学，研究了壳结构，并对组蛋白 (H3) 和 COI 序列进行了系统发育分析，以证实这些属的 neomphalidan 性质。解剖学数据，特别是缺乏感觉乳头、存在单个左肾、左侧受神经支配的交配器官、腺性生殖管、没有卵黄层的卵、一对齿根软骨、穿过心脏下方的直肠和具有单个平衡石的静囊，清楚地将细细线虫、木细线虫和细细线虫排除在斯克尼科和细细线虫之外。 Vetigastropoda 作为一个整体，但强烈表明它在 Neomphalida 中具有系统地位，其中小型螺旋状 Melanodrymia 表现出最相似的地方。这一结论也得到了壳结构（特别是类似于 Nemphalus 的壳孔的存在）和分子树的支持。与鲸鱼瀑布类似，沉没的木材栖息地可能是祖先的常规深层底栖动物与热液喷口栖息地之间的生态桥梁，而热液喷口栖息地则是新蝠鲼科的典型特征。我们认为新肢动物门是腹足动物的一个独立的基础进化枝。
The helicoid microgastropod genera Leptogyra, Xyleptogyra and Leptogyropsis from deep, sunken wood off New Zealand, were originally classified among the poorly defined Skeneidae (Vetigastropoda, Trochoidea) based on shell characters, external morphology and fine-structure of radulae. We investigated the microanatomy and histology of several representatives by means of serial semi-thin sectioning followed by computer-aided 3D-reconstruction, studied the shell structure, and performed phylogenetic analyses of histone (H3) and COI-sequences in order to substantiate the neomphalidan nature of these genera. The anatomical data, in particular the lack of sensory papillae, the presence of a single left kidney, left-side innervated copulatory organs, glandular gonoducts, eggs without a vitelline layer, a single pair of radular cartilages, a rectum passing beneath the heart and statocysts with a single statolith clearly exclude Leptogyra, Xyleptogyra and Leptogyropsis from the Skeneidae and from the Vetigastropoda as a whole, but strongly suggest a systematic position among the Neomphalida, where the small, helicoid genus Melanodrymia shows most similarities. This conclusion is also supported by shell structure (in particular by the presence of shell pores similar to Neomphalus), and by the molecular trees. Similar to whale falls, the sunken wood habitat might have served as an ecological bridge between the ancestral regular deep benthos and the hydrothermal vent habitat otherwise typical for Neomphalida. We argue that Neomphalida is a separate basal clade of rhipidoglossate Gastropoda.