Tectonic history and the biogeography of the freshwater fishes from the coastal drainages of eastern Brazil: an example of faunal evolution associated with a divergent continental margin

Abstract

Tectonic history and the biogeography of the freshwater fishes from the coastal drainages of eastern Brazil: an example of faunal evolution associated with a divergent continental margin Alexandre Cunha RibeiroThe eastern Brazilian coastal drainages are of great biogeographical significance, because of their highly endemic fish faunas. Phylogenetic patterns suggest a close biotic relationship between the rivers that flow into the Atlantic and those on the adjacent upland crystalline shield. However, little has been said on the dynamics of the geological processes causally related to the cladogenetic events between these areas. Distributional and phylogenetic patterns suggest a close association with the geological history of the passive continental margin of South America, from the Cretaceous to the present day. In this area megadome uplifts, rifting, vertical movements between rifted blocks and the erosive retreat of the South American eastern continental margin are hypothesized as the main geological forces controlling the distribution of freshwater fishes. The tectonic activity associated with the break-up of Gondwana and separation of South America and Africa formed six megadomes that control most of the current courses of the main crystalline shield river basins. Except for basins located at the edges of such megadomes, these river systems developed long, circuitous routes over the ancient Brazilian crystalline shield before emptying into the recently opened Atlantic Ocean. Initial cladogenetic events between upland crystalline drainages and Atlantic tributaries were probably associated with vicariant processes, and some ancient basal sister-groups of widespread inclusive taxa are found in these coastal hydrographic systems. Later, generalized erosive denudation resulted in an isostatic adjustment of the eastern margin of the platform. These, along with reactivations of ancient rifts led to vertical movements between rifted blocks and gave rise, in southeastern Brazil, to taphrogenic (rift related) basins. These basins, such as the Taubaté, São Paulo, Curitiba and Volta Redonda basins, among others, captured adjacent upland drainages and fauna. The fossil fishes from the Tremembé Formation (Eocene-Oligocene of Taubaté Basin) exemplify this process. Other taphrogenic systems of Tertiary age were also identified in other segments of the Atlantic continental margin, such as in Borborema province, in NE Brazil, with marked influence over drainage patterns. At the same time, erosive retreat of the eastern margin of the platform successively captured upland rivers, which became Atlantic tributaries evolving associated to main rift systems. The continued nature of these processes explains the mixed phylogenetic and distributional patterns between Atlantic tributaries and the upland crystalline shield areas, especially in the southeastern continental margin, represented by successively, less inclusive sister-groups associated with cladogenetic events from the Late Cretaceous to the present.As drenagens costeiras do...

Molecular phylogeny and biogeographic history of the Neotropical tribe Glandulocaudini (Characiformes: Characidae: Stevardiinae)

“…According to Thomaz et al (2015bThomaz et al ( , 2017, paleoconnections due to sea level retreat played a significant role in the diversification and distributional pattern of the ichthyofauna in lowland along the Brazilian coastal drainages. Although Ribeiro (2006) and Menezes et al (2008) have questioned these events as being the main causal mechanism promoting cladogenesis and speciation within Glandulocaudini, as previously proposed by Weitzman et al (1988), present divergence time results corroborate this hypothesis. Thus, apparently, Pleistocene sea-level fluctuations also influenced the current distribution pattern of Mimagoniates, especially at the population level.…”

“…3). The sharing of fish species that have a relatively restricted distribution, such as L. weitzmani, between the uppermost tributaries of the São Francisco and Paraná rivers may be an evidence of historical relationships between these basins already proposed in previous studies (e.g., Ribeiro, 2006;Buckup, 2011;Camelier, Zanata, 2014). Unfortunately, tissue samples of the specimens from the rio São Francisco basin were not available for molecular analyses, thus the age of the split between these populations of L. weitzmani could not be estimated.…”

“…2). Several authors have already discussed the biogeography of the Glandulocaudini species (e.g., Weitzman et al, 1988;Menezes, Weitzman, 1990;Ribeiro, 2006;Ribeiro et al, 2006;Menezes et al, 2008) and most of the them suggested that the initial diversification of the group took place in upland areas of the ancient Brazilian 10 e170157 [10] crystalline shield, at some paleodrainage of the upper rio Paraná basin. The molecular clock results corroborate this hypothesis since the oldest split occurred among lineages of Glandulocaudini that were restricted to the Brazilian crystalline shield, in the upper rio Paraná basin.…”

“…Thus, apparently, Pleistocene sea-level fluctuations also influenced the current distribution pattern of Mimagoniates, especially at the population level. According to Ribeiro (2006), there are strong evidences that the upper rio Tietê basin suffered a posterior input of an ichthyofauna once found only in coastal rivers where it was endemic. Estimates of divergence times among allopatric populations of M. microlepis proposed herein provide an additional evidence to this hypothesis, since the split between populations from some coastal basins are oldest than those involving population from upper rio Tietê.…”

Phylogenetic relationships of the South American Doradoidea (Ostariophysi: Siluriformes)

“…That hypothesis partially corroborates Higuchi's (1992) results by considering Wertheimeria and Franciscodoras as basal taxa, but differs by considering Kalyptodoras sister to Wertheimeria. That sister-group relationship is interesting because those two taxa are the only ones inhabiting small coastal drainages of eastern Brazil (Ribeiro, 2006), where some relatively old taxa are known (e.g., Copionodontinae, Delturinae). The sistergroup relationships between Wertheimeria and Kalyptodoras was already speculated by Higuchi et al (1990) in their description of Kalyptodoras bahiensis, and Vono & Birindelli (2007) in their study of Wertheimeria.…”