Rio de Janeiro and other palaeodrainages evidenced by the genetic structure of an Atlantic Forest catfish

Abstract

Aim:The disjunct distributions of freshwater organisms along coastal drainages are usually explained by palaeodrainages formed during sea-level retreats that connected currently isolated basins, or by river capture from tectonic adjustments between adjoining watersheds. We evaluate the relative importance of these events on the genetic variation of freshwater fishes inhabiting the Serra do Mar in eastern Brazil, a region with steep mountains and pronounced bays.Location: Coastal river drainages in southeastern Brazil.Taxon: Catfishes of the Trichomycterus alternatus group. Methods:We tested the effects of palaeolandscape connections (GIS-reconstructed palaeodrainages and putative river captures) on the genetic structure (mitochondrial and nuclear markers) of T. alternatus from 15 drainages using phylogenetic reconstructions, lineage delimitation methods and analyses of molecular variance. Results:Trichomycterus alternatus is monophyletic and comprised of three main lineages: two restricted to the basin at its northernmost distribution and another broadly distributed to the south. In the latter, seven major cytb clades were geographically compatible with the eight palaeodrainages, with three incongruences matching river captures previously described for the Guanabara Bay (GB). Shared haplotypes among isolated rivers flowing into GB provide the first molecular evidence of the 'Rio de Janeiro' palaeoriver.Main conclusions: Dispersal via palaeorivers is an important process, but it is not enough to recover the most recent dispersive events. Therefore, integrating both

Phylogeographical Analysis of the Freshwater Gudgeon Huigobio chenhsienensis (Cypriniformes: Gobionidae) in Southern China

“…Freshwater fish in contemporary isolated drainages are often the products of historical river evolutions. Therefore, phylogeographical studies of freshwater fish are significant for understanding the historical reorganization or rearrangements of rivers within and among drainages [ 3 , 4 , 5 , 6 ]. The genetic diversity observed within a species is a key facet of biodiversity that reflects the evolutionary history and adaptability of a species as a whole, or its constituent populations [ 7 , 8 ].…”

Drainage rearrangements and in situ diversification of an endemic freshwater fish genus from north‐eastern Brazilian rivers

“…Not only does the current configuration of disconnected basins represent barriers to gene flow and contribute to divergence processes by allopatry, but recent studies have also shown the effects of past geomorphological events on population genetic diversity and differentiation in Neotropical fishes (e.g. Camelier et al., 2018; Lima et al., 2021; Thomaz et al., 2017). Among these events, past connections between today's isolated basins are forged by either headwater captures or coastal paleodrainages, which can facilitate dispersal between drainages and range expansion, and possibly promote speciation.…”

Hidden diversity and evolutionary diversification in Phalloceros harpagos Lucinda (Cyprinodontiformes: Poeciliidae)

“…TA B L E 2 Summary results of K2P intraspecific and interspecific genetic distances of the partial fragment of cytochrome C oxidase subunit I gene of Phalloceros, considering the grouping according to the delimitation test PTP and GMYC 1. (Lima et al, 2017(Lima et al, , 2021Souto-Santos, Jennings, & Buckup, 2023;Thomaz & Knowles, 2018Thomaz et al, 2015), likely differing by unconformity temporality in common dispersal routes and/or ecological specialisation (Thomaz & Knowles, 2020), which may be closely related to strong incompatibilities of sexual characteristics between sympatric taxa in Phalloceros (Souto-Santos, Jennings, & Thomaz et al, 2019).…”

“…Our findings for the phylogeographic structure of P. harpagos support evolutionary diversification scenarios for species from the Brazilian coastal basins and highlight the important role of palaeodrainages. Discrepancies between patterns of genetic structure and palaeodrainage connectivity may indicate alternative dispersal processes in coastal watersheds (Lima et al, 2017, 2021; Souto‐Santos, Jennings, & Buckup, 2023; Thomaz & Knowles, 2018, 2020; Thomaz et al, 2015), likely differing by unconformity temporality in common dispersal routes and/or ecological specialisation (Thomaz & Knowles, 2020), which may be closely related to strong incompatibilities of sexual characteristics between sympatric taxa in Phalloceros (Souto‐Santos, Jennings, & Buckup, 2023; Thomaz et al, 2019).…”