Fine-Scale Morphological Analysis Reveals Two New Endemic Species of Cryptopygus (Collembola; Isotomidae) from Victoria Land, Antarctica

Among the life forms that have adapted to the harsh Antarctic environment, springtails and mites are the most abundant arthropod groups of the terrestrial ecosystem, both in continental and maritime Antarctica. The study of the systematics of these organisms originates at the beginning of the last century and, in recent years, has received considerable contributions. The taxonomy of springtail species from continental Antarctica has undergone more systematic revisions by way of the integration of modern morphological characters and molecular techniques, the latter of which prompted us to further investigate the morphology of supposed “cryptic species” within the springtail Cryptopygus terranovus from Victoria Land, Antarctica. In this study, a careful morphological analysis was conducted to parse these strongly divergent genetic lineages in order to characterize, from a morphological point of view, these new taxonomic entities. Results from our investigation reveal consistent morphological differences that strongly coincide with geographic and previously reported molecular evidence. With this, we have described two new species, C. fratii sp. nov. and C. dallaii sp. nov., bringing the total number of species of Cryptopygus within continental Antarctica to six.