Provisional checklist of terrestrial heterotrophic protists from Antarctica

Abstract

Heterotrophic soil protists encompass lineages that are both evolutionarily ancient and highly diverse, providing an untapped wealth of scientific insight. Yet the diversity of free-living heterotrophic terrestrial protists is still largely unknown. To contribute to our understanding of this diversity, we present a checklist of heterotrophic protists currently reported from terrestrial Antarctica, for which no comprehensive evaluation currently exists. As a polar continent, Antarctica is especially susceptible to rising temperatures caused by anthropogenic climate change. Establishing a baseline for future conservation efforts of Antarctic protists is therefore important. We performed a literature search and found 236 taxa identified to species and an additional 303 taxa identified to higher taxonomic levels in 54 studies spanning over 100 years of research. Isolated by distance, climate and the circumpolar vortex, Antarctica is the most extreme continent on Earth: it is not unreasonable to think that it may host physiologically and evolutionarily unique species of protists, yet currently most species discovered in Antarctica are considered cosmopolitan. Additional sampling of the more extreme intra-continental zones will probably result in the discovery of more novel and unique taxa.

Phagotrophic protists (protozoa) in Antarctic terrestrial ecosystems: diversity, distribution, ecology, and best research practices

“…The literature reviewed in this study was found by searching variants of relevant keywords (see Thompson et al (2019) for the full list) in Web of Science, SCOPUS, and Google Scholar, and by following citation chains. A list of all studies and a database containing all taxonomic entries pulled from the reviewed literature, including notes on various metadata including sample source, location, and isolation techniques, are included in two supplemental tables (Online Resource 1 and 2).…”

“…Protist taxonomy has undergone major revisions in recent decades at both high and low taxonomic levels (Adl et al 2005(Adl et al , 2007(Adl et al , 2012(Adl et al , 2019Ruggiero et al 2015), and thus the taxonomy for the identified species in the review has been updated (Thompson et al 2019). Protists were traditionally organized, using motility as a distinguishing characteristic, into ciliates, testate amoebae, naked amoebae, and flagellates; only ciliates are still considered monophyletic (i.e., Ciliophora; see Adl et al (2019)).…”

“…However, relatively little work has been done to assess taxonomic diversity in Antarctic terrestrial environments over the last century (Acuña-Rodríguez et al 2014) and the most recent reviews are now two decades old (Smith 1996;Foissner 1998). Thompson et al (2019) constructed a species checklist of phagotrophic protists in Antarctica by reviewing all relevant literature (Online Resource 1), arriving at a total of 236 species and 303 additional taxa not identified to species (Online Resource 2). Using this checklist and its literature reviewed as a baseline, I examine how phagotrophic protist diversity is structured at the regional scale (Terauds et al 2012;Terauds and Lee 2016).…”

Niche Conservatism Drives the Elevational Diversity Gradient in Major Groups of Free-Living Soil Unicellular Eukaryotes

“…The climatic conditions under which they possibly evolved seem to have imposed evolutionary constraints on their ability to adapt to regions with exceedingly hot or cold temperatures, thus in uencing their current diversity patterns, performance and tness. Indeed, nowadays, soil protists exhibit peaks of diversity in warm and humid environments, such as temperate and tropical rain forests [25,26] and declines in diversity towards hot [27] and cold [28] deserts. Soil protist biogeography is usually predicted either by temperature [26], water [29] or both variables (a water-energy balance, [11]).…”

Frozen Zoo: a collection of permafrost samples containing viable protists and their viruses

“…However, more attention has been paid to the testate taxa due to their role as markers in bioindication and paleoenvironmental reconstruction ( Beyens et al 1986 , Vincke et al 2004 , Tsyganov et al 2011 , Taylor et al 2019 ). Antarctic fauna have been studied better than the fauna of the Arctic, with even a checklist published recently ( Thompson et al 2019 ). Concerning Northern Siberia, the available data are almost exclusively limited to testate amoebae ( Beyens and Chardez 1995 , Smith et al 2007 , Bobrov and Wetterich 2012 , Shmakova et al 2013 ).…”