A checklist of halacarid mites (Acari, Halacaridae) found among ascidians (Tunicata, Ascidiacea)

A compilation of marine halacarid mites (Halacaridae) found with ascidians (sea squirts) has been carried out based on published records. In this paper, we listed 19 species found with ascidians, altogether. These 19 species belong to 7 genera, viz. Agaue (3 species), Arhodeoporus (1 species), Copidognathus (8 species), Halacarus (1 species), Lohmannella (2 species), Rhombognathides (1 species), and Thalassarachna (3 species). Most of these reports are from mixed habitats and all these species which were found among ascidians were reported also from other habitats. Most of the cases of halacarids on acidians may be occasional invaders.