Congruence between fish and plant assemblages in drifting macrophyte rafts in Central Amazonia

Abstract

Macrophyte rafts can enhance fish dispersal in the Amazon River basin, and determining whether raft properties (e.g., size and plant species richness) can predict fish species richness and composition is important in order to understand the underlying factors of fish dispersal. We tested for a relationship between the plant species richness and fish species richness in the rafts and determined whether there exists a significant pattern of concordance between rafts composition and fish assemblages in a River-Lake system close to Manaus, Amazonas, Brazil. We estimated the cover of each species of macrophyte and collected fish in 20 macrophyte rafts of different sizes. Macrophyte species richness was not a good predictor of fish species richness. We found a significant correlation between the compositional similarities of macrophytes and fishes when the data for presence/absence were analyzed, but not when abundance data were used. However, the congruence patterns were clearly related to raft size, and we found a correlation between plants and fishes, using both presence/absence and abundance data, when only large rafts were used in the analysis. For small rafts, there were no significant correlations using any type of data. These findings show that the composition of fish assemblage dispersal in the rafts depends on the composition of macrophytes of which the rafts are composed and on stochastic processes of raft splitting.

Habitats determining local frog assemblages within aquatic macrophyte meadows in Amazonia, through species traits filtering

“…These finding is consistent with fish (Dias et al . 2011) and invertebrate assemblages (Vieira & Adis 2000; Adis & Victoria 2001) and suggests high levels of biotic complementarity within macrophyte meadows. However, temporal patterns of species turnover should also be expected as macrophyte meadows may be changed in response to seasonal water‐level fluctuations and wind or heavy rain moving floating macrophytes (Dias et al .…”

“…However, temporal patterns of species turnover should also be expected as macrophyte meadows may be changed in response to seasonal water‐level fluctuations and wind or heavy rain moving floating macrophytes (Dias et al . 2011). Since the overall structure of macrophyte meadows determines the quality of frog habitats and selects species through morphological traits, but changes over time, understanding assemblage structure at temporal scales should be based on multiple sampling of frogs and environmental gradients.…”

Ecology and life-history of Mesonauta festivus: biological traits of a broad ranged and abundant Neotropical cichlid

“…This habitat often becomes fragmented after strong rainfall and these fragments of floating meadows are drifted away with the current, potentially transporting the associated fish fauna along large stretches of the river (Schiesari et al 2003;Dias et al 2011). Although this passive form of vector (unidirectional) transport may explain downstream dispersion, it fails to account for the presence of the species in terra-firme streams, since macrophyte stands do not occur in these forest-shaded environments.…”

The response of amphibian communities to fish and habitat features in Mediterranean permanent ponds

“…Moreover, the abundance of the various fish species in the ponds could highlight the effect of fish on amphibian assemblages and richness of amphibian species. Finally, macrophyte species and physico-chemical characteristics of the water bodies may influence invertebrate assemblages (Dias et al 2011;Kouamé et al 2011) which are prey for fish and adult amphibians.…”

“…Physicochemical features and surrounding land use may influence site selection by many amphibian species (Hartel 2008;Hartel et al 2009;Landi et al 2012). Aquatic macrophytes can affect other animal communities in many different ways: they may provide shelter and refuge for fish and amphibians, as well as being a direct or indirect food source (e.g., Oldham et al 2000;Cheruvelil & Soranno 2008;Santi et al 2010;Dias et al 2011). Density of fish is often higher in large permanent than in small temporary wetlands and the abundance of aquatic macrophytes declines with increasing size and depth of the water body (Woodward 1983;Petr 2000;Mäkelä et al 2004;Hidding et al 2010).…”