DISSERTATION RESEARCH: Molecular Systematics of Needlefishes: Interpreting Heterochrony and Biogeography

论文研究：针鱼的分子系统学：解释异时性和生物地理学

• 批准号: 9622827
• 负责人: Amy McCune
• 金额: --
• 依托单位: Cornell Univ - State: AWDS MADE PRIOR MAY 2010
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 1998-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9622827&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Molecular; Systematics; Needlefishes

9622827 McCUNE The needlefishes (family Belonidae), so-named because of their long needle-like jaws, are fast, predatory fishes found mainly in tropical marine waters. Over the past century, biologists have been intrigued by striking changes of body shape that needlefishes undergo during their life span: juveniles have a long lower jaw, but later develop into adults with long upper and lower jaws. Curiously, adults of the closely-related halfbeak fishes (family Hemiramphidae), have a long lower jaw but never develop the long upper jaw, and thus resemble juvenile needlefishes. Halfbeaks may have arisen from needlefish-like ancestors, or vice versa, through changes in developmental timing (heterochrony) of upper and lower jaw growth. Several needlefish species inhabit South American freshwater rivers. These fish may have invaded freshwater from the Atlantic Ocean, the Pacific Ocean, or both - and the biogeographic patterns among needlefish may also apply to other organisms found in this region. Interpretations of these developmental and biogeographic patterns depends on basic knowledge of how needlefish species are related to one another (a genealogy of species), and this knowledge currently is inadequate. In this study, Nathan Lovejoy, under the supervision of Amy McCune and Richard Harrison, will investigate the relationships of needlefishes by comparing DNA sequences from different species. Specimens of most species are available; a South American collecting trip will complete the list. Mitochondrial and nuclear genes will be amplified from fish tissue samples using the Polymerase Chain Reaction, and the DNA sequences of these genes will be used to construct phylogenetic trees. The resulting insights into needlefish biology will illuminate both the origins of the extraordinary diversity of aquatic species in the tropics, and the mechanisms producing dramatically different body-shapes among these species.

9622827 McCUNE针鱼（Belonidae科），因其长的针状颚而得名，是主要在热带海洋沃茨发现的快速掠食性鱼类。在过去的世纪里，生物学家一直对针叶鱼在其一生中所经历的惊人的身体形状变化感兴趣：幼鱼有很长的下颚，但后来发育成长的上下颚。奇怪的是，近缘的半喙鱼（半喙鱼科）的成年鱼有一个长的下颚，但从来没有发展出长的上颚，因此类似于幼针鱼。半喙可能是从针鱼类祖先，或反之亦然，通过上下颌生长发育时间的变化（异时性）。几种针鱼栖息在南美洲的淡水河流中。这些鱼可能已经从大西洋、太平洋或两者的淡水中入侵--针鱼之间的地理分布模式也可能适用于在这一地区发现的其他生物。对这些发育和地理模式的解释取决于对针鱼物种如何彼此相关（物种谱系）的基本知识，而目前这种知识是不够的。在这项研究中，内森洛夫乔伊，在艾米·麦克库恩和理查德·哈里森的监督下，将通过比较不同物种的DNA序列来调查针鱼的关系。大多数物种的标本都是可用的;南美收集之旅将完成列表。线粒体和核基因将从鱼类组织样品中扩增使用聚合酶链反应，这些基因的DNA序列将被用来构建系统发育树。由此产生的对针鱼生物学的见解将阐明热带水生物种非凡多样性的起源，以及这些物种之间产生显着不同体型的机制。