On the origins of marine‐derived freshwater fishes in South America

Abstract

Aim The South American fish fauna is renowned for its extraordinary diversity. The majority of this diversity is restricted to few major clades that have ancient associations to freshwater habitats. However, at a higher taxonomic level, the South American ichthyofauna is enriched by an extraordinary number of marine derived lineages – lineages that are endemic to freshwaters, but derived from marine ancestors. Here, we test palaeogeographical hypotheses that attempt to explain the origins and exceptional diversity of marine derived fishes in rivers of South America. Location South America. Methods We analysed time‐calibrated molecular phylogenies, ancestral reconstructions and biogeographical patterns for multiple independent marine‐derived lineages. Results Five of the ten marine‐derived lineages in our analysis have biogeographical patterns and stem ages consistent with invasion from the Atlantic Ocean during the Oligocene or Eocene. Drums and pufferfishes reveal patterns and ages that were consistent with the Miocene marine incursion hypothesis. The Amazonian halfbeak is the only lineage younger than the Miocene and invaded Amazonian freshwaters less than a million years ago. Main Conclusion Our results suggest Miocene marine incursions and the Pebas Mega‐Wetland may not explain the high diversity of marine derived lineages in South America. Instead, the Pebas Mega‐Wetland may have created a fertile opportunity for diversification of some, but not all marine‐derived lineages.

Biogeography, habitat transitions and hybridization in a radiation of South American silverside fishes revealed by mitochondrial and genomic RAD data

“…Species in the coastal lagoon systems were not directly derived from ancestral O. argentinensis stock, but derived from other freshwater populations in the “ O. perugiae group” (Figure ). This single transition to freshwater from a marine ancestor in a particular geographical area is a repeated pattern in marine‐derived freshwater fishes, including clingfishes (Conway, Kim, Rüber, Espinosa Pérez, & Hastings, ), anchovies (Bloom & Lovejoy, ), drums and pufferfishes (Bloom & Lovejoy, ), although silversides at large have colonized freshwater habitats in the Americas many times (Bloom et al, ; Campanella et al, ).…”

“…Freshwater colonization of the Amazon and Paraná River Basins by marine lineages such as drums, pufferfishes and anchovies are well documented (Bloom & Lovejoy, ). However, less is known about the origin, relationships, and biogeographical and phylogeographical history of marine‐derived lineages in southernmost South America, where repeated glaciation cycles extirpated freshwater fish populations or relegated them to refugia (Cussac, Fernandez, Gomez, & Lopez, ; Cussac et al, ; Ruzzante et al, , ; Ruzzante, Walde, Macchi, Alonso, & Barriga, ; Zemlak, Habit, & Walde, ; Zemlak, Habit, Walde, Carrea, & Ruzzante, ; Zemlak, Walde, Habit, & Ruzzante, ), and recent changes in sea level resulted in rapid recolonization (Cussac et al, ) or speciation (Beheregaray & Sunnucks, ; Beheregaray, Sunnucks, & Briscoe, ).…”

Effects of adoption of freshwater residency on life‐history ecology of terapontid grunters

“…The macroevolutionary dynamics of freshwater invasions, and the factors driving lineage and ecological diversification (e.g. ecological opportunity and biogeographic events) are being increasingly documented (Betancur‐R et al, 2012; Bloom & Lovejoy, 2017; Davis, Unmack, Pusey, & Pearson, 2012; Davis, Unmack, Vari, & Betancur‐R, 2016a). The effects of these marine‐to‐freshwater transitions on the evolutionary trajectories of specific life‐history strategies and reproductive ecology within invading lineages, however, remain largely unstudied (although see Goto, 1990; Katoh & Nishida, 1994; VanGerwen‐Toyne et al, 2012; Closs, Hicks, & Jellyman, 2013; see Jones, Augspurger, & Closs, 2017 for studies contrasting diadromous versus freshwater residency).…”

Habitat transitions alter the adaptive landscape and shape phenotypic evolution in needlefishes (Belonidae)

“…However, other fish groups exhibit greater lability of habitat occupancy, with evolutionary reconstructions suggesting multiple independent transitions between marine and freshwater habitats. For example, pufferfishes (Santini et al, 2013; Yamanoue et al, 2011), drums (Lo et al, 2015), herring, longfin herrings, and anchovies (Bloom & Lovejoy, 2012; Bloom & Lovejoy, 2014), sculpins and other cottoid fishes (Buser et al, 2019), stingrays, and needlefishes (Bloom & Lovejoy, 2017) include both marine species and freshwater species distributed across multiple continents. These trans‐marine/freshwater clades provide optimal study systems for understanding how habitat shifts alter the adaptive landscape and drive the evolution of ecological novelty and morphological disparity (Davis, Unmack, Pusey, Pearson, & Morgan, 2014).…”