权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

The paleontological study on the origin and evolutin of submarine cave ostracodes from coral reefs.

珊瑚礁海底洞穴介形类起源与演化的古生物学研究.

基本信息

批准号：
06640601
负责人：
TABUKI Ryoichi
金额：
$ 1.02万
依托单位：
University of the Ryukyus
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

The puropose of this study is to reveal the faunal characteristics of the submarine cave ostracodes from the Ryukyu Islands, and the evolutionary process of the new troglobitic saipanettid genus.The characteristics of the cave assemblages from "Daidokutsu" of Ie Island are enumerated as follows. (1) Living individuals are very rare. The rare occurrence of living ostracodes probably reflects the oligotrophic conditions of submarine caves. (2) The ostracode assemblages from "Daidokutsu" consist mostly of shallow water elements from outside the cave. Exceptionally, three saipanettid species, including 'new genus' (1sp.), are all thought to have derived from deep-sea ancestors. (3) Cytheraceans from the "Daidokutsu" samples are relatively low in species diversity and individual abundance compared to other ostracode taxa. The ostracode assemblages from various habitats of open sea floor environments have been dominated by cytheraceans since the middle Jurassic.A new troglobitic saipanettid genus, only found from submarine caves of the Ryukyu Islands, possibly derived from the saipanettid Cardobairdia, a deep-sea muddy bottom inhabitant, or its relatives. It is likely that the new genus has successfully colonized hard substrata in caves, particularly exploiting the crevices on cave walls and ceilings as its microhabitat. The new genus may have adapted to this cryptic habitat in response to strong cytheracean competetors, and to predators such as gastropods that do not survice well in dark and oligotrophic submarine caves. Insofar as well preserved appendages have been investigated, the new genus differs from the closely related genera Saipanetta and Cardobairdia in having fewer setae without any fine structure. While crawling, the new genus keeps its carapace widely gaped. The ability to open the carapace widely is one of the primitive behavioral features of podocopids.

本研究旨在揭示琉球群岛海底洞穴介形虫的区系特征，以及新的涡球型塞班螺属的演化过程。(1)活着的个体非常稀少。活体介形类的罕见可能反映了海底洞穴的营养贫乏条件。(2)“Daidokutsu”的介形类组合主要由洞外的浅水元素组成。例外的是，包括新属(1 sp.)在内的三个塞班螺目物种都被认为是深海祖先的后代。(3)与其他介形虫类群相比，“Daidokutsu”样本中的苏铁类物种多样性和个体丰度相对较低。自中侏罗世以来，各种开阔海底环境中的介形虫组合一直以海鞘动物为主。仅在琉球群岛的海底洞穴中发现了一个新的斜带虫属，可能起源于深海泥质海底栖息的塞班虫或其近亲。新属很可能已经成功地在洞穴中定居了坚硬的底物，特别是利用洞穴墙壁和天花板上的裂缝作为其微生境。这个新属可能已经适应了这个神秘的栖息地，以应对强大的野猫类竞争者，以及在黑暗和营养不良的海底洞穴中不能很好存活的腹足类等捕食性动物。根据保存完好的附属物的研究，该新属不同于近缘关系密切的塞帕内特属和Cardobairdia属，具有较少的刚毛，没有任何细微的结构。在爬行时，新属保持其甲壳大张大口。足足类的原始行为特征之一是能够广泛地打开甲壳。