Genetic characterization of native and introduced populations of the neotropical cichlid genus Cichla in Brazil

Abstract

A molecular phylogenetic analysis based on mitochondrial 16S ribosomal DNA and Control Region sequences from native and introduced populations was undertaken, in order to characterize the introduction of Cichla (peacock bass or tucunaré) species in Brazil. Mitochondrial DNA haplotypes found in introduced fish from Minas Gerais state (southeastern Brazil) clustered only with those from native species of the Tocantins River (Cichla piquiti and C. kelberi), thereby suggesting a single or, at most, few translocation acts in this area, even though with fish from the same source-population. Our study contributes to an understanding of the introduction of Cichla in regions of Brazil outside the Amazon basin, and adds phylogenetic data to the recently describe Cichla species, endemic from the Tocantins-Araguaia basin.

Analysis of propagule pressure and genetic diversity in the invasibility of a freshwater apex predator: the peacock bass (genus Cichla)

“…This is in accordance with our morphological observations, since intermediate morphotypes were observed within the native range only. Carvalho et al (2009b) also did not find any evidence of shared haplotypes within CP and CK invasive populations, even in areas of sympatry. Besides the relatively small number of fish analyzed (mean=15.3, Table 1), evidence suggests that hybridization is not an important factor in the invasive capability of Cichla.…”

“…Despite the reduction in genetic diversity, the population from the Itumbiara reservoir (the only site where the two species are found in sympatry) and the Furnas reservoir had levels of genetic diversity not significantly different to the native population ( Table 1). The similarity in the genetic composition in Itumbiara can be attributed to multiple introductions at this site with fish from Tocantins River (Carvalho et al, 2009b).…”

“…Introductions were likely carried out from a single river, the Tocantins River (Amazon basin). A low diversity of maternal lineages was detected in the invasive populations, except for the reservoir closest to the source population, suggesting different propagule pressures in the invasive range (Carvalho et al, 2009b).…”

“…However, the influence of multiple introductions (i.e., intense propagule pressure) and the invasive genetic paradigm have not yet been resolved since spatial and temporal aspects of multiple introductions were also associated with propagule pressure and the ability of a species to spread (Dlugosch & Parker, 2008). Genetic data have been useful to provide information on the frequency in which a species is introduced into a specific area, the size of introductions and the subsequent pattern of genetic structure in the new range (Banks et al, 2010;Carvalho et al, 2009b;Dlugosch & Parker, 2008;Henry et al, 2009). Nonetheless, it is yet unclear what role genetics may have in the propagule pressure effect (Allendorf & Lundquist, 2003).…”

“…While Cichla species were apparently introduced into northeastern Brazil in the late 1940s by government agencies for establishing fish breeding farms, no information was available regarding their origin. Applying a molecular phylogenetic analysis based on mitochondrial 16S ribosomal DNA and control region sequences (Carvalho et al, 2009b) identified the source of Cichla species introduced in four different river basins in Southern Brazil. Introductions were likely carried out from a single river, the Tocantins River (Amazon basin).…”