New mites Terraphagus antipodus gen. n., sp. n. and Neohyadesia minor sp. n. (Acarina: Astigmata: Algophagidae) from islands of the Southern Ocean

Mites are a diverse and important component in the soils of the Southern Ocean islands, but for many groups, their taxonomy and biogeography is little studied. This paper reports the Algophagidae, a poorly known family, from the New Zealand region for the first time. The study used soil samples from seabird burrows, brackish algal wrack samples and a museum collection to recover specimens. Terraphagus antipodus gen. n., sp. n. is described from grey petrel Procellaria cinerea burrow soil on the Antipodes Islands, New Zealand. The axillary organ is confined to the dorsum; the epigynal apodeme ends are fused with the ends of coxal apodeme II; seta 2a and ω2 are absent, and the famulus is bilobed. Males have the sternum fused to coxal apodemes II; the tarsal setae of legs I, III and IV of the male are modified for mate guarding. The short stout legs I and II end in huge spines in females as e, d, q, s, wa and hT. From brackish algal wrack, Lake Forsyth/Wairewa, Canterbury, New Zealand, another algophagid Neohyadesia minor sp. n. is described and illustrated. The new species is the smallest known algophagid. A neohyadesid collected in 1961 is newly reported here from Eudyptes sp. penguin rookery mud from North Head, Macquarie Island. These records further extend the known microhabitats of the family to the allochthonous marine seabird nutrient flow into islands in the New Zealand region and make Neohyadesia Hughes and Goodman, 1969 present in all Southern Ocean provinces.