“…While the causative agent of this newly detected disease remains unknown, we have performed a pilot analysis of the most likely potential causative agents recorded in literature: pathogens and metal bioaccumulation (Avila-Villa et al, 2012;Dragičević et al, 2021a;Kouba et al, 2010;Li et al, 2007;Tavabe et al, 2019;Vincent & Lotz, 2007;Wu et al, 2008). Hepatopancreas has a central role in detoxification (Wu et al, 2008) and multiple studies have demonstrated high metal accumulation in hepatopancreas (Fikirdeşici-Ergen, 2020;Gherardi, 2006;Xiong et al, 2020) and related histopathological changes similar or identical to those identified within this study (Li et al, 2007;Tavabe et al, 2019;Wu et al, 2008). Pilot analyses of water and sediment metal load revealed that both the Korana River and the reference (unpolluted) site in the Mrežnica River appear as generally clean watercourses with only somewhat higher concentrations of dissolved Mn and Fe in the surface water of both rivers, and additionally higher concentrations of As and Ba (4.5 times and 1.5-2.5 times, respectively) in the Korana River, when compared with pristine karstic rivers in and is also in line with other studies demonstrating differences between native and invasive alien crayfish in their metal requirements and rates of metal uptake, accumulation, detoxification and excretion (Gherardi, 2006).…”