Phylogenetics and Historical Biogeography of Otocinclus

该项目将进行为期三年的研究， 系统学和分类学，自然历史，和 耳鲶属的鲶鱼。 这群大约20人 该物种属于淡水中最大的辐射之一 新热带鱼类，甲鲶科，包括 超过600种 这些鱼是 巴西东南部大西洋沿岸地区的鱼类区系， 其中包括大西洋海岸森林的残余， 被确定为高度生物多样性的地区， 降解 研究这一特定鱼类群体的相关性 在于他们对理解复杂的 历史进程塑造了 生活在巴西大西洋沿岸地区的生物。 一些固有的生物学特性，以及以前的工作 对耳孔虫属的研究具有重要意义 实现这些更广泛的目标。 这一群体的代表 鱼类目前广泛分布在整个南部 美洲，在每一条主要河流中都有一个或多个物种 流域 它们的体积小，加上能力低 分散和广泛的地理分布，使他们倾向于 这种地理分析。 知识 耳孔虫属物种之间的关系，加上类似的 有代表性的其他动植物群的数据 在大西洋沿岸地区，将提供基本数据， 重建这一地区的地理历史 并寻求共同的因果因素负责产生的 今天观察到的生物群体的分布特性。 然后，这些信息可以用于制定保护和 管理战略。 尽管它们很重要，但基础生物学和 这些鱼类的分类学知之甚少;这种系统学 组必须修订，新的物种描述和说明，他们的 确定相互关系，并定义当前分布 在了解大西洋的地理学取得进展之前 沿海地区可以。 形状，颜色模式， 和形态特征将被用来确定 耳孔虫属的分类学界限。 远征2 大西洋沿岸和邻近河流鲜为人知的地区 系统将进行采样以前没有记录 物种，并确定其分布。 一般鱼类学 将在各大博物馆收藏和保存标本 在北美和南美，形成了物质基础， 继续研究。 实验室形态学研究将 用于重建耳孔虫属物种之间的关系。 该项目将提供一个额外的组成部分， 建立一个全面的数据集， 新热带区的地理假说。

This project will conduct a three year study of the systematics and taxonomy, natural history, and biogeography of the catfishes of the genus Otocinclus. This group of approximately 20 species belongs to one of the largest radiations of freshwater fishes in the Neotropics, the family Loricariidae, which includes over 600 species. These fishes are an important component of the fish fauna of the Atlantic coastal region of southeast Brazil, which includes remnants of the Atlantic Coastal Forest and has been identified as a region of high biodiversity under severe threat of degradation. Relevance of the study of this particular group of fishes lies in their contribution toward understanding the complex historical processes which have shaped the biogeography of organisms inhabiting the Atlantic coastal region of Brazil. Several inherent biological properties, as well as previous work on the group, lend particular significance to study of Otocinclus for achieving these broader goals. Representatives of this group of fishes are presently widely distributed throughout South America, with one or more species occurring in every major river drainage basin. Their small size, coupled with low capabilities for dispersal and wide geographic distribution, predispose them for this kind of biogeographic analysis. Knowledge of the relationships among species of Otocinclus, coupled with similar data for other groups of animals and plants having representatives in the Atlantic coastal region, will provide the basic data for reconstructing the biogeographic history of this particular region and seeking the common causal factors responsible for producing the distributional properties of groups of organisms observed today. This information can then be used to formulate conservation and management strategies. Despite their importance, aspects of the basic biology and taxonomy of these fishes are poorly known; the systematics of this group must be revised, new species described and illustrated, their inter-relationships determined, and present distributions defined before progress in understanding the biogeography of the Atlantic coastal region can be made. Analyses of shape, coloration pattern, and morphological characteristics will be used to determine the taxonomic limits to the species of Otocinclus. Expeditions to two poorly known areas of the Atlantic coastal and neighboring river systems will be undertaken to sample previously undocumented species and to define their distributions. General ichthyological collections will be made and specimens deposited in major museums in both North and South America, forming the material basis for continued study. Laboratory based morphological studies will be used to reconstruct the relationships among Otocinclus species. This project will then provide one additional component toward building a comprehensive dataset for testing competing biogeographic hypotheses in the Neotropical region.