Tracking the history of an invasion: the freshwater croakers (Teleostei: Sciaenidae) in South America

Abstract

In this study, the competing hypotheses of single vs. double colonisation events for freshwater Pachyurinae (Sciaenidae) in South America is tested and the historical biogeography of the expansion of this clade within the continent is reconstructed based on phylogenetic analysis. Parsimony and Bayesian inference (BI) for 19 marine and freshwater species assigned to Sciaenidae, Haemulidae and Polypteridae were determined based on partial sequences of the mitochondrial 16S and cytochrome b genes and fragments of the nuclear Tmo‐4C4 and rhodopsin genes. A parsimonious ancestral character reconstruction of euryhalinity was performed on a clade of families of closely related fishes to evaluate the role of ecological fitting in the colonisation of freshwater by a marine sciaenid. The parsimony and BI phylogenetic hypotheses for the concatenated sequences supported the monophyly of the freshwater Sciaenidae. Divergence of the two freshwater clades of Sciaenidae, Pachyurinae and Plagioscion, occurred within the Amazon Basin. Within Pachyurinae, two clades were recovered: one composed of species from the Amazon and the Paraná Basin and a second with representatives from the São Francisco and south‐eastern Atlantic basins. The results were compatible with the hypothesis of a single colonisation event of South American freshwater habitats by a marine lineage. The hypothesis of gradual adaptation to freshwater was rejected in favour of the hypothesis of ecological fitting. Sciaenidae, or a subordinate lineage within the family, is ancestrally capable of withstanding exposure to low‐salinity habitats, which putatively facilitated the colonisation of freshwater habitats. The subsequent diversification and expansion of Pachyurinae across South America followed this colonisation and replicated the general pattern of the area relationships of South American river basins for several other fish groups.

Genetic relationships between landlocked and coastal populations of Lycengraulis grossidens (Engraulidae) in south-eastern South America: evidence for a continental colonisation route with secondary transitions to the coastal region

“…This hypothesis agrees with the scenario described by Cooke et al (2012) and Boeger et al (2015) for the freshwater croaker (Plagioscion: Sciaenidae), which suggests that the migration route followed by Plagioscion was from the Amazon River to the Parana Basin. The geological history of separation and interconnection between the Amazonian and Parana systems is complex, but there are estimates that the basins split 10 million years ago with some evidence of headwater-capture events in the Parana system by the Amazon occurring within the past 10 million years (Hubert and Renno 2006).…”

“…We hypothesise that the landlocked population from the Uruguay River has restricted gene flow with regard to the coastal population and that this freshwater population reached its current distribution through a north-to-south continental route putatively associated with ancient connections between the Amazon and Parana basins, as occurred for Sciaenidae species (Cooke et al 2012;Boeger et al 2015). According to this scenario, L. grossidens would have reached the marine environment from the Parana basin, from which it would have expanded its distribution along the south-eastern Brazilian coast.…”

First true brackish-water nudibranch mollusc provides new insights for phylogeny and biogeography and reveals paedomorphosis-driven evolution

“…Such a zone occurs in estuarine areas [ 21 , 22 ] and in other transitory water bodies sometimes with limited exchange of oceanic water, like the Baltic Sea, or the inner part of fjords. Furthermore, since brackish waters repeatedly have been colonized by marine taxa, this often leads to intricate phylogenetic patterns, as has recently been revealed from several metazoan phyla [ 23 , 24 ]. Habitat shifts have played a fundamental role in the evolution of the pulmonate molluscs, which is the largest terrestrial metazoan group after insects and chordates, as they shifted from marine to terrestrial environments also through intermediate stages in intertidal and brackish waters [ 25 ].…”

Genetic relationships of Plagioscion squamosissimus (Perciformes, Sciaenidae) from five Neotropical river basins evaluated using mitochondrial atpase6/8 gene sequences

“…The identification of haplotypes in regions where populations are native will be useful for comparison with the haplotypes present in the regions where the species are introduced. In regions where P. squamosissimus is native, few phylogenetic and biogeographic studies employing molecular markers (Cooke et al, ; Santos et al, ; Boeger et al, ) have been conducted. Avise et al .…”

“…The identification of haplotypes in regions where populations are native will be useful for comparison with the haplotypes present in the regions where the species are introduced. In regions where P. squamosissimus is native, few phylogenetic and biogeographic studies employing molecular markers (Cooke et al, 2012;Santos et al, 2013;Boeger et al, 2014) have been conducted. Avise et al (1987) observed that mitochondrial DNA haplotypes of some of these populations have specific geographic locations, introducing phylogenetics into discussions of population structure.…”