The compositon, abundance and biomass of the benthic fish fauna were studied along a 6 km stretch of the GuariticoRiver. This water course is located in the western plains of Venezuela and belongs to the Apure River floodplain system.Monthly collections from June, 1990 to January, 1991 were made by means of a small trawling apparatus rigged todugout canoes according to the design of López-Rojas et al. (1984). 42 fish species were identified with a dominanceof species from the orders Siluriformes and Gymnotiformes. The fish assemblage differed markedly from other Venezuelan river systems. Seasonally, higher diversity and evenness were observed at the high water phase while the abundance, relative biomass and CPUE were higher at low water.
