摘要：Using multivariate analyses of fish community and environmental data, we explored associations among13 fish species and 9 ecological guilds and identified ecological gradients that explain patterns in the fish communityof the La Antigua River (Veracruz, Mexico). Altitude, distance to ocean, stream width, and water temperature werethe most important variables explaining community composition. Sites with high altitudes (> 1 393 m), cold water(< 17ºC), located far from the ocean (> 100 km) and less than 5 m wide were dominated by non-native Onchorhynchusmykiss. Many sites exclusively inhabited by native poeciliids were also narrow (< 2 m), but were located at intermediatealtitudes (1 039-1 400 m) and distances to the ocean (> 80 km, < 100 km) and had warmer water temperatures (> 20ºC).Because 7 guilds were exclusive to a single species, results from the guild analysis were very similar to species-specificanalyses. Higher species and guild diversity were found in wider sites (> 5 m), sites with lower altitudes (< 600 m),and sites closer to the ocean (< 71 km). Variables related to human influence did not explain trends found in the fishcommunities.
关键词：Biología; Ecología; Ictiología;Veracruz; fish community; Mexican rivers; La Antigua River; ecological gradients
