Checklist of oribatid mites (Acari: Oribatida) from two contrasting boreal fens: an update on oribatid mites of Canadian peatlands

A checklist of the oribatid mite species from two boreal fens in Northern Ontario, Canada is presented. 174 peat soil samples, collected between 2015–2020, yielded a heterogeneous assemblage of 80 species, 57 genera and 33 families. Species richness and diversity were significantly higher in a Sphagnum-dominated fen (69 species) compared to a Carex-dominated fen (51 species), and although 40 species were found at both sites, overall composition was significantly different between the two sites. We also present an update to the seminal work of Behan-Pelletier and Bissett (1994) on Oribatida of Canadian peatlands with 45 new species records for peatlands. Records for the parthenogenetic families Brachychthoniidae Thor, 1934 and Suctobelbidae Jacot, 1938 were considerably expanded, but other families such as Punctoribatidae, Thor, 1937 remain poorly represented in Canadian peatlands. Taken together, species richness estimates range from 86–105 species based on our sampling and the number of undescribed species recorded suggests that the oribatid mite fauna still need further examination to encompass their actual biodiversity in peatlands. We report that the oribatid mite fauna of Canadian peatlands comprise 186 species that includes all published records as of February 2021 and species presented here.