The Mite Fauna (arachnida: Acari) of Gough Island, South Atlantic Ocean: Natural Colonization, Endemism and Human Introduction

Gough Island is part of the Tristan da Cuhna archipelago in the South Atlantic Ocean. The island’s significant conservation status necessitates determining the fauna and its origin. This study reports the occurrence of 63 mite species at Gough, adding greatly to the six previously known species for the island. These records constitute 30 confirmed species (cr), 13 morphological variants of nominate species (nr), 15 likely new species with no clear close relative (sp. nov.) and five currently undetermined species (sp). The fauna comprises predominantly Mesostigmata (24 species) and Oribatida (21), with fewer Prostigmata (8) and Astigmatina species (10). Habitat specificity across high-altitude, low altitude and marine boulder beach (and supralittoral) biotopes was comparatively low for the mesostigmatid mites and high for the oribatid and astigmatine mites. Global geographical realm associations based on the confirmed and morphological-variant species are greatest for the Antarctic (19 species), followed by the Holarctic (13 species). Whereas human introductions originate predominantly from the Holarctic, involving mainly mesostigmatid mites, obligatory marine mites are natural colonizers from the Antarctic realm. The numerous morphological variants and new species imply significant isolation, speciation and endemism. Overall, human introduction accounts for 20