Browsing by Autor "Carlos A. Lasso"

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Conservación y tráfico de la tortuga matamata, Chelus fimbriata (Schneider, 1783) en Colombia: un ejemplo del trabajo conjunto entre el Sistema Nacional Ambiental, ONG y academia
(2018) Carlos A. Lasso; Fernando Trujillo; Mónica A. Morales-Betancourt; Laura Amaya; Susana Caballero; Beiker Castañeda
Se presentan los resultados de una iniciativa interinstitucional (Corpoamazonia, Corporinoquia, Instituto Humboldt, Universidad de Los Andes y Fundación Omacha), donde se verificó, con herramientas moleculares, que varios lotes de tortugas matamata (Chelus fimbriata) decomisadas en la ciudad de Leticia, departamento del Amazonas, Colombia, correspondían a ejemplares capturados en la Orinoquia y cuyo destino final era aparentemente Perú, como parte de una red de tráfico de fauna. Basados en este hallazgo, 2 corporaciones liberaron 400 individuos neonatos en el en el río Bita y la Reserva Natural Privada Bojonawi en el departamento del Vichada, Orinoquia colombiana. Se evidencia el tráfico de esta especie probablemente hacia Perú, donde la comercialización de tortugas es legal. Se recomienda el uso de protocolos de identificación genética para determinar y controlar la procedencia geográfica de tortugas decomisadas a futuro, como paso previo y necesario para su liberación.
Evidence of history in explaining diversity patterns in tropical riverine fish
(Wiley, 2005) Pablo A. Tedesco; Thierry Oberdorff; Carlos A. Lasso; Milton Zapata; Bernard Hugueny
Abstract Aim Documentation of the ongoing effect of rain forest refuges at the last glacial maximum (LGM) on patterns of tropical freshwater fish diversity. Location Tropical South and Central America, and West Africa. Methods LGM rain forest regions and species richness by drainage were compiled from published data. GIS mapping was applied to compile drainage area and contemporary primary productivity. We used multiple regression analyses, applied separately for Tropical South America, Central America and West Africa, to assess differences in species richness between drainages that were connected and disconnected to rain forest refuge zones during the LGM. Spatial autocorrelation of the residuals was tested using Moran's I statistic. We added an intercontinental comparison to our analyses to see if a historical signal would persist even when a regional historical effect (climate at the LGM) had already been accounted for. Results Both area and history (contact with LGM rain forest refuge) explained the greatest proportions of variance in the geographical pattern of riverine species richness. In the three examined regions, we found highest richness in drainages that were connected to the rain forest refuges. No significant residual spatial autocorrelation was detected after considering area, primary productivity and LGM rain forest refuges. These results show that past climatic events still affect West African and Latin American regional and continental freshwater fish richness. At the continental scale, we found South American rivers more species‐rich than expected on the basis of their area, productivity and connectedness to rain forest refuge. Conversely, Central American rivers were less species‐diverse than expected by the grouped model. African rivers were intermediate. Therefore, a historical signal persists even when a regional historical effect (climate at the LGM) had already been accounted for. Main conclusions It has been hypothesized that past climatic events have limited impact on species richness because species have tracked environmental changes through range shifts. However, when considering organisms with physically constrained dispersal (such as freshwater fish), past events leave a perceptible imprint on present species diversity. Furthermore, we considered regions that have comparable contemporary climatic and environmental characteristics, explaining the absence of a productivity effect. From the LGM to the present day (a time scale of 18,000 years), extinction processes should have played a predominant role in shaping the current diversity pattern. By contrast, the continental effects could reflect historical contingencies explained by differences in speciation and extinction rates between continents at higher time scales (millions of years).
Mamíferos presentes en los alrededores del Centro de Investigaciones Ecológicas La Macarena (CIEM), Parque Nacional Natural Tinigua, Meta, Colombia
(2026) Carlos A. Lasso; Ivan Dario Escobar Martinez; Monica Andrea Morales - Betancourt; Pablo Roberto Stevenson; Andrés Lomelín; Juan de la Cruz Amado
Phylogeography, genetic diversity and population structure of the freshwater stingray, Paratrygon aiereba (Müller & Henle, 1841) (Myliobatiformes: Potamotrygonidae) in the Colombian Amazon and Orinoco basins
(Taylor & Francis, 2020) Maira A. Rizo-Fuentes; Camilo A. Correa‐Cárdenas; Carlos A. Lasso; Mónica A. Morales-Betancourt; Dalia C. Barragán‐Barrera; Susana Caballero
The freshwater stingray Paratrygon aiereba have coloration, osteological and morphometric variations that could suggest the existence of more than one species in Colombia. In order to evaluate the phylogeography, population structure and genetic diversity for P. aiereba distributed in the Amazon and Orinoco basins, we amplified Cytochrome oxidase subunit 1 (COI) partial region of mitochondrial DNA (mtDNA) in 50 samples from eight different sub-basins. Our results suggest three phylogroups and a vicariance event occurred 43 million years ago proposing how Paratrygon diverged into the basins. A high population structure (ΦST = 0.692; p < 0.005) and a value of (K) of 3 were defined. A high genetic diversity within phylogroups was found: Phylogroup A (h = 0.64; π% = 2.48), Phylogroup B (h = 0.552; π% = 1.67), and Phylogroup C (h = 0.49; π% = 0.73). These results should be considered in local management plans, conservation programs and reclassification in at least Amazon and Orinoco.