A decade of invasion: distribution patterns and temperature influence on Kellicottia bostoniensis (Rousselet, 1908), in the Upper Uruguay River Basin

Abstract: Aim This study reports the spread dynamics of the non-native species Kellicottia bostoniensis across all reservoirs in the Upper Uruguay River Basin, a decade after its initial recorded occurrence. Additionally, it assesses the role of temperature in shaping its distribution within this subtropical system. Methods Spatial and temporal variations in K. bostoniensis density and environmental parameters were analyzed over a 12-month period. Generalized Linear Models (GLMs) were applied to evaluate the relationship between environmental parameters and species density, providing insights into the key drivers of its distribution. Results The connectivity among reservoirs within the cascade system of the Upper Uruguay River has facilitated the continued spread of the non-native species K. bostoniensis. The detection of this species in all reservoirs a decade after its first recorded occurrence suggests its successful establishment and widespread distribution within the system. The observed high densities were likely influenced by the consistently low temperatures characteristic of subtropical regions, particularly those associated with the Serra Geral Mountains, with a more pronounced effect during colder months. Conclusions The widespread distribution of K. bostoniensis across the Upper Uruguay River Basin underscores its potential for further expansion into similar environments, driven by a combination of environmental and anthropogenic influences. The species’ ability to disperse and establish in diverse habitats highlights the critical need for continuous monitoring and management strategies to mitigate its spread and prevent additional ecological invasions.