Nebela tincta protists2/18/2023 ![]() ![]() (1934) Geobiologie of inleiding tot de milieukunde. This study clearly gives food for thoughts and hopefully will stimulate the community of testate amoeba researchers to further explore how amoebae colonise new habitats.īaas Becking, L.G.M. However it may be possible to develop an optimal type of trap for studying aerial dispersal of testate amoebae. The traps were indeed initially not designed for such a study but were nevertheless useful. ![]() The study of Wanner and colleagues also shows that it is not straightforward to design traps for studying aerial dispersal of testate amoebae. The first step is indeed for an amoeba to become airborne and this may not be trivial depending where the species live. Globally it provides useful data on actual wind dispersal of amoebae. Locally it informs on the mechanisms that determine primary and secondary colonisation of soil and other habitats and at which temporal scale testate amoebae can be used as bioindicators. Such research is important at the local as well as global scales. seven years of soil development and therefore concluded that testate amoebae are valuable indicators of initial ecosystem development and utilisation. The authors estimated that the shift from stochastic to deterministic community pattern takes place after ca. These results also suggest that initial colonisation will be rather stochastic but that as more and more amoebae are deposited on a given place the full potential community will soon be present and community composition will therefore soon be controlled by local processes such as environmental filtering. Therefore a viable population can become established rather rapidly on a newly exposed surface, provided that a source population is present nearby. Their small size and lighter shells should potentially allow them to be transported more easily than larger taxa, but this is not what Wanner and colleagues observed.Įxtrapolating form their results, Wanner and colleagues estimated that on average 61 individual amoebae (living + dead) were deposited per square meter each day. Indeed small euglyphids are likely to be more numerous in the upper soil horizons and the better drained and exposed microsites from which they can be expected to have more chances to be lifted up by the wind. across 100-1000km of ocean) passive dispersal must therefore be extremely low.Īlso it is rather surprising that the dominant taxa recorded on the traps were not small euglyphids but mid-size arcellinids. Therefore although this study shows that amoebae can “fly”, they don’t do so in massive numbers even close to the ground and near source populations. The overall abundance was low with little over 80 specimens recorded in total. 40µm and 60µm in diameter ( Phryganella acropodia and Centropyxis sphagnicola). The two most commonly found species were respectively ca. eurystoma, Difflugia lucida, Phryganella acropodia, Tracheleuglypha dentata, Trigonopyxis arcula, Trinema complanatum, Trinema lineare, and Trinema penardi. They exposed traps for periods ranging from 16 to 42 days and recorded 12 testate amoeba species (excluding unidentifiable specimens): Centropyxis aerophila, C. The system was initially designed to study seed dispersal but proved to also be useful to study microorganisms. The petri dishes were used as passive, sticky traps for airborne organisms and contained no growth media. Wanner and colleagues used sticky traps: 15cm diameter plastic petri dishes in which filter paper was attached using a paraffin-based balm, which also covered the filters. An elegant recent study by Wanner and colleagues contributed to filling this important gap ( Wanner et al., 2015). But, to my knowledge, observational and experimental studies on wind dispersal of testate amoebae are very rare. 9 µm diameter) could potentially do so ( Wilkinson et al., 2012). 40-60µm diameter) were unlikely to travel over large distances and certainly incapable of crossing oceans while the smaller ones (e.g. A recent modelling study showed that the medium to large sized testate amoebae (i.e. It is therefore perhaps surprising that not much experimental research has been done to quantify the amoebae that are transported by wind. everything is everywhere, but, the environment selects ( Baas Becking, 1934, de Wit and Bouvier, 2006)). ![]() Observations such as this have led to the idea that microscopic organisms could travel far and colonise all potentially favourable habitats (i.e. He sent the sample to Ehrenberg who observed it under his microscope and found many protists ( Darwin, 1846). Darwin had collected dust that had fallen on the Beagle while sailing off the coast of Africa. Since the early days of protistology it has been known that testate amoebae can be transported passively by wind. “ I’m learning to fly but I ain’t got wings Laboratory of Soil Biology, University of Neuchâtel ![]()
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