Diferenciación morfométrica del Género Corbicula (Megerle von Mühlfeld, 1811) en las cuencas Grijalva, Usumacinta y Papaloapan

Abstract

Southeastern Mexico has an important network of river and wetland ecosystems, where invasive species are recorded that represent a threat to biodiversity and produce alterations in natural ecosystems. In this study, the species of the Corbicula genus were identified based on the morphometric differentiation of the organisms collected in the Grijalva, Usumacinta and Papaloapan basins. The organisms belong to the Reference Collection on Aquatic Organisms of the Southeast: Macroinvertebrates and Fish of ECOSUR, collected in diurnal samplings with a multi-habitat effort in 25 locations between the years 2013 to 2018, the physicochemical parameters of the water were also recorded. Regarding water parameters, the maximum values ​​of pH (8.5), temperature (29°C), and oxygen saturation (76.6%) were recorded in the Usumacinta basin, while conductivity (546 mScm-1) and salinity (0.27‰) were recorded in Papaloapan. 200 organisms corresponding to each basin were selected, these were measured (length, width and height) and weighed individually. Of the total organisms analyzed, 59% of the abundance was for Corbicula fluminea (Cfl), while Corbicula largillierti (Cla) represented 41%. The Grijalva and Usumacinta basins recorded the highest abundance of Cfl with 84% and 75%, on the contrary, in Papaloapan Cla is the predominant species representing 80% of the records in this basin. The highest mean values ​​for measurements and weight were for Cla. In the case of Cfl, the maximum mean value for weight was recorded in the Grijalva basin, while the length, height and width were in the Usumacinta basin. For both species, the mean values ​​for all measurements and weight were recorded in the Papaloapan basin. This work contributes with a new invasive species in the Grijalva, Usumacinta and Papaloapan basins.