A new Najadicola species (Acari: Hydrachnidia: Pionidae) from Asia

In this paper, we describe Najadicola loeiensis sp. nov. (Pionidae: Najadicolinae), a new water mite species from the Loei River, a tributary of the Mekong River in Thailand. The only other species in this small genus, N. ingens (Koenike, 1895), inhabits North America. Our novel tropical Asian species can be distinguished from N. ingens by the shape of coxal plates and body size. N. loeiensis sp. nov. is a parasite of the inner cavity of freshwater mussels (Bivalvia: Unionidae) as its Nearctic congener.