Coordinated Dispersal and Pre-Isthmian Assembly of the Central American Ichthyofauna

Abstract

We document patterns of coordinated dispersal over evolutionary time frames in heroine cichlids and poeciliine live-bearers, the two most species-rich clades of freshwater fishes in the Caribbean basin. Observed dispersal rate (DO) values were estimated from time-calibrated molecular phylogenies in Lagrange+, a modified version of the ML-based parametric biogeographic program Lagrange. DO is measured in units of “wallaces” (wa) as the number of biogeographic range-expansion events per million years. DO estimates were generated on a dynamic paleogeographic landscape of five areas over three time intervals from Upper Cretaceous to Recent. Expected dispersal rate (DE) values were generated from alternative paleogeographic models, with dispersal rates proportional to target area and source-river discharge volume, and inversely proportional to paleogeographic distance. Correlations between DO and DE were used to assess the relative contributions of these three biogeographic parameters. DO estimates imply a persistent dispersal corridor across the Eastern (Antillean) margin of the Caribbean plate, under the influence of prevailing and perennial riverine discharge vectors such as the Proto–Orinoco–Amazon river. Ancestral area estimation places the earliest colonizations of the Greater Antilles and Central America during the Paleocene–Eocene (ca. 58–45 Ma), potentially during the existence of an incomplete Paleogene Arc (∼59 Ma) or Lesser Antilles Arc (∼45 Ma), but predating the GAARlandia land bridge (∼34–33 Ma). Paleogeographic distance is the single best predictor of DO. The Western (Central American) plate margin did not serve as a dispersal corridor until the Late Neogene (12–0 Ma), and contributed relatively little to the formation of modern distributions.

Comparative phylogeography of trans‐Andean freshwater fishes based on genome‐wide nuclear and mitochondrial markers

“…The first supported pattern (ATR +TUI) corresponds to a presumably physical connection between the Atrato and Tuira basins that likely occurred in synchrony with the formation of the Darién Isthmus and other major physiographic features that emerged since the Pliocene (Bagley & Johnson, 2014;Lundberg et al, 1998;Montes et al, 2015;O'Dea et al, 2016;Picq et al, 2014). As reported by several other studies on freshwater fishes, tree topologies depict clustering between the Caribbean-Pacific slope populations (including Atrato) and the near-Atlantic slope populations, a signal of the historical association among these basins that have drained through the same continental slope (Bagley & Johnson, 2014;Bermingham & Moritz, 1998;Chakrabarty, 2006;Concheiro-Pérez et al, 2007;Ingley, Reina, Bermingham, & Johnson, 2015;Lovejoy et al, 2010;Matamoros et al, 2015;McMahan et al, 2013;Tagliacollo, Duke-Sylvester, Matamoros, Chakrabarty, & Albert, 2017). This pattern is also corroborated by shared faunal compositions among these basins (Maldonado-Ocampo, Buckup et al, 2012;Maldonado-Ocampo, Usma-Oviedo et al, 2012;Maldonado-Ocampo, Usma-Oviedo et al, 2012;Matamoros et al, 2015), including two sister species of the catfish family Ariidae that inhabit fresh and brackish waters: Notarius bonillai (ATR and MAG)…”

Interdependent Phenotypic and Biogeographic Evolution Driven by Biotic Interactions

“…Other relevant biogeographic processes are not being considered, but are relatively straightforward to incorporate in future versions of the model. Characteristics of the delimited geographical regions, such as distance from each other (Landis et al 2013), geographical area (Tagliacollo et al 2015), connectivity (Kadmon and Allouche 2007), age of area availability (e.g., on volcanic islands, Landis et al 2018), and resource availability (Tilman 1985) will provide key information when inferring biotic interactions. Furthermore, incorporating abiotic optima, as determined by the different regional environments, could be used to distinguish abiotic from biotic forces acting upon trait and range evolution.…”

Continental cichlid radiations: functional diversity reveals the role of changing ecological opportunity in the Neotropics

“…Cichlids and poecillids dominate Mesoamerican freshwater communities, in contrast with the much higher diversity of ostariophysan fishes, largely characiformes and siluriformes, in South America [23,24]. This difference among continents has led many to suggest that secondary freshwater fishes such as cichlids and poecillids filled an 'Ostariophysan vacuum', with the comparatively depauperate ecosystems of Central America providing new and remarkable opportunities for diversification among these early colonists [21,[25][26][27][28].…”