“…To the best of our knowledge, current data present the first successful development and application of non-invasive sampling techniques to detect halarachnid mite infestations in free-ranging pinnipeds. Orthohalarachne attenuata and Orthohalarachne diminuata were already reported in both free-ranging and captive South American sea lions in the past ( Finnegan, 1934 ; Kutzer and Burtscher, 1983 ; Morgades et al, 2006 ; Gomez-Puerta and Gonzales-Viera, 2015 ; Seguel et al, 2018b ; Ebmer et al, 2022 ), including co-infestations with both species ( Calderón-Mayo, 2015 ). However, compared to other otariids like California sea lions, Northern fur seals or South American fur seals ( Dahme and Popp, 1963 ; Kim et al, 1980 ; Páez, 2007 ; Katz et al, 2012 ; Gastal et al, 2016 ; Kuzmina et al, 2018 , Kuzmina et al, 2021 Seguel et al, 2018a , 2018b ; Pesapane et al, 2021 ), comparably few studies specifically addressed halarachnid mites in free-ranging Otaria flavescens, so far.…”