| Abstract: | Dibble ED, Pelicice FM. Influence of aquatic plant‐specific habitat on an assemblage of small neotropical floodplain fishes.Ecology of Freshwater Fish 2010: 19: 381–389. © 2010 John Wiley & Sons A/S Abstract – This study investigated the effects of plant‐specific habitat on the distribution of young and small adult fishes in lagoons of the Upper Paraná River floodplain, Brazil. We compared fish catch per unit effort (CPUE) and species richness and used an indirect gradient analysis to investigate fish‐plant relationships within three aquatic macrophytes beds (Cabomba furcata, Eichhornia azurea, Nymphaea amazonum), and explored microhabitat influence (indexed by eight variables related to physical structure and water quality) on the structure of fish assemblages. Rarefaction analysis was used to compare fish species richness among the vegetated habitats. We captured a total of 1599 fish constituting 23 species, 7 families and 3 orders. Fish CPUE and species richness increased relative to microhabitat structure innate to the macrophytes; higher CPUE and richness were observed in C. furcata beds, a submerged aquatic macrophyte with finely dissected leaves. On the contrary, N. amazonum, a species that provides low microhabitat complexity, harbored fewer individual fish and number of species. Reproduction dynamics, hydrology and the amount of available plant‐generated habitat structure (surface effect) contributed to the disproportionally high number of individuals captured during the dry season. Our data suggest that the microhabitat physical structure (e.g., edge distance, stem density and patch size) provided by macrophyte beds in the lagoons of the Upper Paraná River may play a more important role than physicochemistry (e.g., oxygen, temperature and pH) at mediating distribution patterns of small‐sized fishes. |
