Diversity and abundance of free-living nematodes from Carlini station, Isla 25 de Mayo/King George Island, Antarctica: A case study in pristine and disturbed soils

This study describes the soil nematodes of King George Island (Isla 25 de Mayo) in Antarctica through molecular identification, abundance, and structure analysis. Nematodes are key organisms in terrestrial ecosystems, with important roles in nutrient cycling and trophic networks. Despite the harsh conditions in the extreme environment of Antarctica, these organisms have managed to adapt and survive. Soil samples were collected from pristine and disturbed areas, and morphological and molecular analyses were conducted to identify the nematode species present. Abundance, trophic groups, maturity indices, and colonizer-persister values ( cp ) were analyzed and compared between the sampling sites. The molecular results revealed four genera of Antarctic nematodes ( Coomansus , Calcaridorylaimus , Eudorylaimus , and Plectus ), and the phylogenetic relationships of these nematodes with others found in Antarctica were established. ANOSIM and SIMPER statistical analysis showed significant differences in nematode abundance between pristine and disturbed areas. The analysis of the nematode assemblage through MI , EI , and SI showed less disturbance at the pristine sites than at the anthropic sites. Further studies should be carried out at the Carlini Station and 25 de Mayo/King George Island to learn more about the structure of the nematode community and how they are affected by anthropic practices in Antarctic environments.