Quelques aspects du peuplement thécamoebien des sols de la province de Québec (Canada)

Abstract

A census of Thecamoebae in 295 soil samples, mostly from the Province of Quebec (Canada), has yielded a total of 143 species and varieties. As a whole, these Thecamoebae populations differ little from those found in comparable biotopes throughout the world. A new family, Distomatopyxidae, and a new genus, Puytoracia (Euglyphidae), have been studied.Biogeographic, biocenotic, and ecological aspects are discussed. Mathematical analysis (factor analysis of affinities) has led to the definition of 16 associations of species for the various biotopes.

A new level of confidence: biogeography, morphometry and ecology of enigmatic Cyclopyxis puteus Thomas, 1960 (Amoebozoa: Arcellinida: Netzeliidae)

“…It has also been reported in South America: Brazil and Paraguay (Bonnet, 1979); French Guiana (Coûteaux & Chardez, 1981) and Peru (Bobrov et al, 2019), Central America: Mexico (Bonnet, 1977a;Bobrov et al, 2013) as well as North America: Canada (Puytorac et al, 1972;Bonnet,1974;Lousier, 1982;Beyens et al, 1990). Ad- ditional evidence for the cosmopolitan dispersion of C. puteus is that the species is registered also in Asia: Indonesia (Bonnet, 1992), Nepal (Bonnet, 1977b(Bonnet, , 1981, North Korea (Golemansky & Todorov, 1991), Thailand (Bonnet, 1987;Golemansky & Todorov, 2000), Vietnam (Bobrov et al, 2010), Africa: Demo- cratic Republic of the Congo (Siemensma, 2019(Siemensma, -2023; Gabon (Bonnet, 1969); Guinea (Golemansky, 1962); remote sub-Antarctic archipelago Îles Crozet (part of the French Southern and Antarctic Lands, Vincke et al, 2006) and even as part of Antarctic microbiota (Sudzuki, 1979). During the expedition in Guinea, Golemansky (1962) found shells that have the general appearance of C. puteus, but with much smaller dimensions (diameter 72 μm; depth 60 μm; pseudostome 18-20 μm; diameter/depth ration -1.2; diameter/external opening -4.0).…”

“…First discovered near Pessac in southwestern France by Thomas (1960), C puteus has been recorded from many localities in Europe, including Belgium (Chardez, 1961;Chardez et al, 1987), Bulgaria (Deltshev et al, 1999;Todorov, 2001;Bankov, 2022, Todorov, unpublished), Czech Republic (Balik, 1994), France (Bonnet, 1972, 1993, Decloitre, 1977, Poland (Golemansky, 1970), Russia (Balik, 1992;Bobrov, 2001;Payne et al, 2020;as fossil record in Bobrov et al, 2003as fossil record in Bobrov et al, , 2004, Slovakia (Balik, 1997) and in the area between Belgium, North France, Luxemburg and Netherland (no information for a particular country or sample point in Chardez & Lambert, 1981 ). It has also been reported in South America: Brazil and Paraguay (Bonnet, 1979); French Guiana (Coûteaux & Chardez, 1981) and Peru (Bobrov et al, 2019), Central America: Mexico (Bonnet, 1977a;Bobrov et al, 2013) as well as North America: Canada (Puytorac et al, 1972;Bonnet,1974;Lousier, 1982;Beyens et al, 1990).…”

“…Records of solitary specimens came from calcimorphic soil on karst (Bonnet, 1992), humic soil without plant cover (Balik, 1992), humus collected from bamboo roots (Bonnet, 1987), flooded savannah (Bonnet, 1997), rhizosphere of epiphytic plants and area with cut off forest, which was subse-quently burned (Coûteaux & Chardez, 1981). Additional information about its ecological preferences is provided by Bonnet (1974), who registered it in both acidic and carbonated soils in Québec province, Canada. Accidental findings of C. puteus in Sphagnum mosses (Chardez et al, 1987;Golemansky & Todorov, 1991;Bankov, 2022) and freshwater habitats like a small swamp in rice field (Golemansky & Todorov, 1991) or forest stream (Golemansky & Todorov, 2000) may be due meteorological conditions like wind and/or heavy rain that brought single specimens from adjacent areas.…”

Global distribution modelling of a conspicuous Gondwanian soil protist reveals latitudinal dispersal limitation and range contraction in response to climate warming

“…However, as most soil testate amoebae are able to encyst, they can survive during long periods of drought and frost (Bonnet, 1964), which explains their presence also in hot and cold deserts (Bamforth, 2004;Bamforth et al, 2005;Fernández, 2015;Pérez-Juárez et al, 2017). Very long-term survival seems possible as attested by the finding of viable protists including amoebae in 30,000-year-old permafrost (Shatilovich et al, 2005).…”

“…A dubious unconfirmed record from Antarctica (an apparent albeit surprising confusion with Difflugia vas, now either Lagenodifflugia vas or Pontigulasia spectabilis (Murray, 1910;Penard, 1902Penard, , 1911 was excluded, but the record from King George Island, 120 km off the coast of the Antarctic Peninsula (Zapata & Matamala, 1987) is validated despite being from lake sediments, which is not the typical habitat of A. vas. Records from Vancouver, Canada (Penard, 1911), Iceland (Decloitre, 1965), Nepal (Bonnet, 1977), Hawaii and Japan (Richters, 1908) likely corresponded to mis-identifications. Finally, records with insufficient information available to infer a location with the required degree of certainty were also excluded (see Text S1 for a more detailed discussion of the critical data points).…”