Internat. Rev. Hydrobiol. 94 2009 1 67 – 90 DOI: 10.1002/iroh.200711070 DOUGLAS RODRÍGUEZ-OLARTE*, 1, 2 , DONALD C. TAPHORN3 and JAVIER LOBÓN-CERVIÁ2 1Colección Regional de Peces. Laboratorio de Ecología. Departamento de Ciencias Biológicas. Decanato de Agronomía. Universidad Centroccidental Lisandro Alvarado, UCLA. Barquisimeto, Lara, Venezuela, Apartado postal 400; e-mail:
[email protected] 2Museo Nacional de Ciencias Naturales, CSIC. Departamento de Ecología Evolutiva. C/. José Gutiérrez Abascal, 2. ES-28066 Madrid, Spain 3UNELLEZ. Vice-Rectorado de Producción Agrícola. BioCentro. Museo de Zoologia, Colección de Peces, Mesa de Cavaca, Guanare, Estado Portuguesa,Venezuela Research Paper Patterns of Freshwater Fishes of the Caribbean Versant of Venezuela key words: biogeographic provinces, coastal rivers, classification and ordination analyses, biodiversity, dispersion, hotspots Abstract We delineate local and regional biogeographic provinces that suggest patterns of species richness, and primary and secondary freshwater fish distributions along the Caribbean coast of Venezuela. We use presence-absence records and classification and ordination models. Patterns at local and regional scales varied markedly such that primary species dominated humid drainages and secondary species dominated arid drainages or transition provinces. Species rich areas, and the presence of narrowly endemic species correlate with patterns of historical isolation and hydrographic refuges. Patterns of species distributions across arid drainages suggest that close proximity of coastal marine drainages allows dispersion and exchange of species. This pattern is particularly evident among secondary species. Hotspots of species richness and endemisms are identified and are recommended as priorities for conservation. 1. Introduction 1.1. General Overview South America contains perhaps the greatest species richness of freshwater fishes in the world.