A new species of Agauopsis (Acari, Halacaridae) from South Korea belonging to A. brevipalpus group

A new marine halacarid mite of the genus Agauopsis Viets, 1927 is recorded from mussels in the intertidal bedrock of the southern coast of South Korea. Agauopsis bisetosa n. sp. belonging to the A. brevipalpus group, is characterized by an ‘H’-shaped areola on the anterior dorsal plate, two pairs of costae on the posterior dorsal plate, a tectum with a truncate anterior margin, posterior epimeral plate with two ventral setae, telofemur I with one ventral and two ventromedial dentate spines, and tibia II with one ventral and one ventromedial dentate spines. Notably, the presence of two ventral setae on the posterior epimeral plate is a unique characteristic of the new species. This study deals with a description of A. bisetosa n. sp., accompanied by detailed illustrations drawn under a differential interference contrast microscope and scanning electron microscope photomicrographs. Additionally, it includes a character comparison table of the A. brevipalpus group and a key for known Agauopsis species in the northwest Pacific, both including the new species.