Character Acquisition During the Transition to Amphibious Life in the Oxudercine Fishes

0111241 Graham本研究调查了虾虎鱼亚科鱼类两栖生活和空气呼吸的专门化。 包括在oxudercines物种，如弹涂鱼，这是高度两栖和呼吸空气，以及几个较少-和完全非两栖物种。 研究了弹涂鱼陆生性的相关性状及其在弹涂鱼亚科中的变化顺序。 DNA序列分析将证实oxudercine物种之间的系统发育关系。 不同oxudercines的比较研究考察了鳃和辅助空气呼吸表面之间的功能关系，例如，考虑到双呼吸表面的存在如何影响呼吸，离子和酸碱平衡以及含氮废物排泄等特性。 还将研究如何鳃和辅助呼吸结构的功能oxudercine从力竭运动恢复。 通过对氧胺眼的比较，将揭示与空中视敏度相关的变化是如何发展的。 在日本和澳大利亚的实地考察将把物种特异性专业化与行为和微生境分布相关联，以确定不同程度的陆地适应如何影响oxudercine分布和自然历史。在脊椎动物中，oxudercines是独一无二的，它提供了从水生生物到两栖生物的系统发育连续体的进化“快照”沿着，因此是研究在这一过渡过程中发生的特征变化序列的理想选择。因此，这项研究有助于了解3.6亿年前泥盆纪脊椎动物入侵土地期间发生的一系列变化。

0111241 GrahamThis study investigates the specializations for amphibious life and air breathing of fishes in the goby subfamily Oxudercinae. Included among the oxudercines are species such as the mudskippers, which are highly amphibious and air-breathing, as well as several less- and entirely non-amphibious species. The research studies the characters associated with mudskipper terrestriality and the sequence of change these characters have undergone within the Oxudercinae. DNA sequence analyses will confirm the phylogenetic relationships among the oxudercine species. Comparative study of different oxudercines examines the functional relationship between the gills and auxiliary air-breathing surfaces considering, for example, such questions as how the presence of dual respiratory surfaces affects properties such as respiration, ionic and acid-base balance, and nitrogenous waste excretion. Also studied will be how the gills and auxiliary air-breathing structures function in oxudercine recovery from exhaustive exercise. Comparisons of oxudercine eyes will reveal how changes related to aerial visual acuity developed. Fieldwork in both Japan and Australia will correlate species-specific specializations with behavior and microhabitat distribution in order to establish how different degrees of terrestrial adaptation affect oxudercine distribution and natural history. The oxudercines are unique among the vertebrates in providing evolutionary "snap-shots" along the phylogenetic continuum extending from aquatic to amphibious life, and are thus ideal for studying the sequence of character changes that occurred over the course of this transition. This study therefore contributes to an understanding of the suite of changes that occurred during the invasion of land by the vertebrates in the Devonian Period, 360 million years ago.