Distribution of invasive Procambarus clarkii (Girard, 1852) (Decapoda: Astacidea: Cambaridae) in South Korea, with a study of the spatial variation of benthic macroinvertebrate taxa.

This article focuses on the distribution, growth, and ecological impact of the invasive red swamp crayfish, *Procambarus clarkii*, in South Korea. Since its introduction around 1930, *P. clarkii* has expanded to 24 regions, primarily in the southwestern part of the country, exhibiting positive allometric growth and rapid population increase despite eradication efforts. Using the maximum entropy (MaxEnt) model, the study predicts further spread influenced mainly by temperature-related climatic variables. Analysis of benthic macroinvertebrate communities revealed that substrate composition and water quality significantly affect species distribution, with *P. clarkii* occupying diverse habitats and potentially competing with native aquatic species. The findings underscore the need for continued monitoring and management to mitigate ecological risks posed by this invasive species and associated pathogens threatening native crayfish populations.