Newly appeared microarthropods, mainly terrestrial mites, in the Yukidori Zawa of Langhovde and surrounding ice-free areas, which constitute the Syowa Oasis, East Antarctica

The 28th Japanese Antarctic Research Expedition explored terrestrial microarthropods in 11 ice-free areas around Syowa Station in East Antarctica. In addition to the previously known species of Nanorchestes antarcticus in Endeostigmata, and Tydeus erebus and Neoprotereunetes minutus in Prostigmata, seven terrestrial mite species were newly identified in this study: Antarcticola meyeri in Oribatida, and Nanorchestes bellus, Nanorchestes lalae, Nanorchestes sp. in Endeostigmata, and Tydeus sp., Eupodes sp., and Stereotydeus meyeri in Prostigmata. The wingless insect Friesea grisea (Collembola) and the winged insect Liposcelis sp. (Psocoptera) were also newly confirmed. In the Yukidori Zawa, known as Syowa Oasis, eight species of free-living terrestrial mites, including three potentially undescribed species, were collected out of the 12 species of microarthropods recorded during this expedition. In this study, A. meyeri was found in two ice-free areas of East Antarctica: Yukidori Zawa in Langhovde and Mt. Riesel Larsen in Amundsen Bay. The distribution of A. meyeri is restricted to East Antarctica, which is the third discovery of this species endemic to East Antarctica. Until now, only N. antarcticus had been reported near Syowa Station, but observation of only five morphological characteristics revealed the existence of three species: N. bellus, N. sp., and N. lalae. The high diversity of microarthropods, especially terrestrial mites, in the Antarctic oasis around Syowa Station suggested the need to continue conserving this ice-free area as the Syowa Oasis.