“…Since they were first described in 1847 ( Allman, 1847 ), halarachnid mites have been documented in more than a dozen marine mammal species worldwide ( Rolbiecki et al, 2018 ), yet few reports include estimates of prevalence ( Kenyon et al, 1965 ; Dunlap et al, 1976 ; Kim et al, 1980 ; Fay and Furman, 1982 ; Baker, 1987 ; Munro et al, 1992 ; Dailey et al, 2005 ; Kuiken et al, 2006 ; Alonso-Farré et al, 2012 ; Gastal et al, 2016 ; Seguel et al, 2018a , 2018b ) and our prior study in southern sea otters ( Pesapane et al, 2018 ) is the only study to estimate nasopulmonary mite prevalence in California marine hosts. Our summary data suggests that nasopulmonary mite infestation is the norm among California sea lions (74.1%), northern fur seals (73.3%), and northern elephant seals (46.6%), while infestation is less common among harbor seals (18.7%) and Guadalupe fur seals (8.8%) ( Table 3 ).…”