Phylogeographic pattern of Jenynsia multidentata(Cyprinodontiformes: Anablepidae) in the southern boundary of the Brazilian Subregion, Argentina

Abstract

The Atlantic drainage basins are located in the southern Pampean area, in the southernmost part of the Brazilian subregion. Tectonic and paleoclimatic phenomena, occurring during the Quaternary, have currently isolated these basins from the present hydrographic system. Their ichthyofaunal composition is similar to that of hydric systems located further northward. Jenynsia multidentata is a species with wide distribution in the Atlantic drainage basins, as well as in those Northern basins. Here we investigated the phylogeographic pattern of Jenynsia multidentata and analyzed its relationships with the paleoclimatic and geologic history of the region. The analysis of the population's assemblage showed moderate genetic diversity, demographic equilibrium and marked genetic structure in the populations that occupy the extremes of the distributional range. The populations in the center of the range did not present genetic diversity, sharing a single haplotype. These results allow inferring that the presence of Jenynsia multidentata in the area results from historical demographic processes that are independent but complementary. In turn, these processes could arise from paleoclimatic changes occurred during the Quaternary.Las cuencas de pendiente atlántica del área pampeana Austral son el límite meridional de la subregión Brasílica. Fenómenos tectónicos y paleoclimáticos ocurridos durante el Cuaternario han dejado aisladas a estas cuencas del diseño hidrográfico actual. La composición íctica de estás cuencas es similar a la de los sistemas hídricos ubicados más al norte. Jenynsia multidentata es una especie con un amplia distribución en las cuencas de pendiente atlántica, como así también, en las cuencas ubicadas al norte. En el presente trabajo se investigó el patrón filogeográfico de Jenynsia multidentata, y se examinó la relación entre este patrón y la historia paleoclimática y geológica de la región. En el análisis del conjunto de poblaciones se encontró evidencia de una moderada diversidad genética, equilibrio demográfico, y una marcada estructura poblacional, en las poblaciones que ocupan los extremos de la distribución. Mientras que en las poblaciones que ocupan el centro de la distribución no se encontró diversidad genética presentando un único haplotipo. De los resultados obtenidos se infiere que la presencia de Jenynsia multidentata en el área es el resultado de procesos demográficos históricos independientes pero complementarios. A su vez, estos procesos podrían surgir de los cambios paleoclimáticos ocurridos durante el Cuaternario.

Quaternary refugia and secondary contact in the southern boundary of the Brazilian subregion: comparative phylogeography of freshwater fish

“…In the case of J. multidentata it was possible to amplify eleven individuals, which were added to the preexisting ones, using the primers and under the conditions described in Bruno et al (2013). Negative controls were performed in all cases to verify the absence of contamination.…”

“…The general goal of this work is to analyze and compare the phylogeographic pattern of two teleostean species that are co-distributed in the basins of the Southern Pampean Area: Jenynsia multidentata and Corydoras paleatus. The sequences for J. multidentata are those of Bruno et al (2013) with the addition of new individuals. Both species are widely distributed and have documented fossil records within the area.…”

Same place, different stories: Disparate evolutionary trends of mygalomorph spiders from the Peripampasic orogenic arc

“…Although the Peripampasic orogenic arc offers an excellent framework for testing biogeographical hypotheses, only two recent studies have investigated the factors driving local diversification (Moreno et al, 2018; Silva et al, 2018). In addition, several studies focused on revealing distribution patterns have been conducted on plants (Crisci‐V et al, 2001; De La Sota, 1967; Moreno et al, 2018), lichens (García & Del Palacio, 2021), scorpions and harvestmen (Acosta, 2002), spiders (Ferretti et al, 2014; Ferretti, González, & Pérez‐Miles, 2012), moths (Silva et al, 2018), coleoptera (Roig‐Juñent & Quiroga, 2021) and fishes (Bruno et al, 2013).…”

Ichthyofauna of the lower course of the Negro river drainage, Patagonia Argentina

“…Species from Brazilian and Patagonian lineages coexist along the basins of the Colorado and Negro rivers, defining a zone of zoogeographic transition recognized as an ecotone (Arratia et al 1983;Almirón et al 1997). The specific richness of the Negro and Colorado river basins is higher than the other Patagonian rivers as a consequence of the historical connections of these systems with northern aquatic systems that resulted in the presence of Characiformes and Cyprinodontiformes in these rivers (Cione and Barla 1997;Casciotta et al 1999;Bruno et al 2013). Questions arise regarding the number of species present in these basins, the extent of their distribution areas, and the cause of their presence in the rivers, whether natural or introduced by anthropogenic activities (Baigún et al 2002).…”