Reduction of a native fish fauna by alien species: an example from Brazilian freshwater tropical lakes

Abstract

The consequences of introducing Cichla cf. monoculus Spix & Agassiz, Astronotus ocellatus (Agassiz) and Pygocentrus nattereri Kner into lakes in the River Doce basin, Brazil, on richness, diversity and efficiency of aquatic macrophytes as natural refugia to native fishes was investigated. Samples were taken from lakes with and without alien fishes in areas with and without aquatic macrophytes. The presence of alien fishes reduced richness and diversity of the native fish community. The refugia function, which could be attributed to the clustering of aquatic macrophytes, does not exist in these lakes probably because the alien fishes exploit such habitats for reproduction. Since introductions threaten the native fish diversity of the region, studies on regional dispersion and factors that minimise the spread of alien fishes are needed.K E Y W O R D S : alien species, Brazil, habitat heterogeneity, River Doce State Park, tropical fish community.

Reproductive biology of the peacock bass Cichla piquiti (Perciformes: Cichlidae), an exotic species in a Neotropical reservoir

“…Considering that species of the genus Cichla are piscivorous and cause negative impacts on native ichthyofauna, which can lead to the local extinction of its prey (Zaret & Paine, 1973;Latini & Petrere, 2004), C. piquiti may cause an ecological and ichthyofaunal disequilibrium in the Itumbiara Reservoir. Thus, experimental fisheries must be implemented to evaluate the fish community of the reservoir, and if necessary, methods of population control must be implemented for this exotic species.…”

“…The wide distribution of the peacock bass out of its natural habitat is related to several factors that increase its possibilities of survival, including an opportunistic piscivore alimentary habit (Jepsen et al, 1997), a preference for spawn in lentic environments where food supply for larvae and young is abundant (Zaret, 1980), and the construction of nests and biparental care (Muñoz et al, 2006). The negative impact of these introductions on natural fish communities is well known, where Cichla drastically reduces the abundance and diversity of native species (Zaret & Paine, 1973;Santos et al, 1994;Latini & Petrere, 2004;Novaes et al, 2004). In the Itumbiara Reservoir, the present study area, the peacock bass was first registered in 1980, and is now the most abundant piscivore fish (Santos, 1999).…”

Red swamp crayfish: biology, ecology and invasion - an overview

“…Species moved beyond the limits of their normal geographic ranges by human actions usually have strong ecological impacts (Witte et al, 1992;Parker, et al, 1999;Hall and Mills, 2000;Latini and Petrere, 2004) and the effects of biological invasion in freshwater habitats seem to be greater than in terrestrial ecosystems, especially because freshwater invasive species have a greater tendency to disperse (Sala et al, 2000;Beisel, 2001). Additionally, the importance of freshwater environments to humankind is enormous and modifications on its services will have a strong impact on human welfare.…”

Spatial pattern of a fish assemblage in a seasonal tropical wetland: effects of habitat, herbaceous plant biomass, water depth, and distance from species sources

“…However, cattle farming in this system has led to replacement of native vegetation by exotic species, as an alternative to improving animal productivity (Junk, 2000). Many studies show that exotic species can reduce the survival, density, biomass, species richness, diversity and evenness as well ecosystem process in worldwide terrestrial (Hoffmann et al, 2008;Hejda et al, 2009) and aquatic environments (Latini & Petrere, 2004;Pelicice & Agostinho, 2009). Thus, the replacement of native vegetation by exotic pasture can affect the structure and dynamics of fish assemblages (Baber et al, 2002) by altering the composition and abundance of native plant species, as well as the hydrological conditions of the landscape.…”