scholarly journals The curse of taxonomic uncertainty in biogeographical studies of free-living terrestrial protists: a case study of testate amoebae from Amsterdam Island

2009 ◽  
Vol 36 (8) ◽  
pp. 1551-1560 ◽  
Author(s):  
T. J. Heger ◽  
E. A. D. Mitchell ◽  
P. Ledeganck ◽  
S. Vincke ◽  
B. Van de Vijver ◽  
...  
2016 ◽  
Vol 56 (2) ◽  
pp. 138-145 ◽  
Author(s):  
J. Q. Ouyang ◽  
Á. Z. Lendvai ◽  
I. T. Moore ◽  
F. Bonier ◽  
M. F. Haussmann

2019 ◽  
Vol 132 ◽  
pp. 128-134 ◽  
Author(s):  
L.H. Azevedo ◽  
L.G. Leite ◽  
J.G. Chacon-Orozco ◽  
M.F.P. Moreira ◽  
M.P. Ferreira ◽  
...  

1989 ◽  
Vol 1 (3) ◽  
pp. 215-224 ◽  
Author(s):  
Paul A. Broady

The survey concentrated on algal communities but also gathered information on mosses, lichens and microfauna. All 23 nunataks in the Rockefeller and Alexandra mountains (77°00′–78°30′S, 152°–154°W) were visited, including ones both with and without nutrient enrichment from bird colonies. Over 30 species of algae were recorded with Cyanobacteria and Chlorophyta dominant as in other regions of continental Antarctica. Diatoms were not found. The most frequent algae were Cyanothece aeruginosa, Gloeocapsa spp., Oscillatoriaceae, Nostoc sp., Pseudococcomyxa simplex, Stichococcus bacillaris, cf. Desmococcus vulgaris, Prasiola crispa and Prasiococcus calcarius. Although lichens were the most visually prominent vegetation, free-living algae occurred in the widespread ‘non-aquatic’ habitats as epilithic, chasmoendolithic and edaphic communities as well as being epiphytic on the sparse moss cushions. Aquatic habitats were few and there were only three small ponds on or adjacent to nunataks. On ablating ice, cryoconite ponds contained Homoeothrix cf. rivularis, recorded for the first time in Antarctica. Preliminary identifications show 23 species of lichens and six species of mosses. No mites and collembola were seen. Samples contained testate amoebae, ciliate protozoa, rotifers and tardigrades but no nematodes.


2019 ◽  
Vol 124 (3) ◽  
pp. 379-388 ◽  
Author(s):  
J L H Cardós ◽  
M Prieto ◽  
M Jylhä ◽  
G Aragón ◽  
M C Molina ◽  
...  

AbstractBackground and AimsIn order to re-establish lichen symbiosis, fungal spores must first germinate and then associate with a compatible photobiont. To detect possible establishment limitations in a sexually reproducing cyanolichen species, we studied ascospore germination, photobiont growth and photobiont association patterns in Pectenia plumbea.MethodsGermination tests were made with ascospores from 500 apothecia under different treatments, and photobiont growth was analysed in 192 isolates obtained from 24 thalli. We determined the genotype identity [tRNALeu (UAA) intron] of the Nostoc cyanobionts from 30 P. plumbea thalli from one population. We also sequenced cyanobionts of 41 specimens of other cyanolichen species and 58 Nostoc free-living colonies cultured from the bark substrate.Key ResultsNot a single fungal ascospore germinated and none of the photobiont isolates produced motile hormogonia. Genetic analyses revealed that P. plumbea shares Nostoc genotypes with two other cyanolichen species of the same habitat, but these photobionts were hardly present in the bark substrate.ConclusionsDue to the inability of both symbionts to thrive independently, the establishment of P. plumbea seems to depend on Dendriscocaulon umhausense, the only cyanolichen species in the same habitat that reproduces asexually and acts as a source of appropriate cyanobionts. This provides support to the hypothesis about facilitation among lichens.


Protistology ◽  
2017 ◽  
Vol 11 (2) ◽  
Author(s):  
I. Kh. Alekperov ◽  
◽  
N. Yu. Snegovaya ◽  
E. N. Tahirova ◽  
◽  
...  
Keyword(s):  

Botany ◽  
2013 ◽  
Vol 91 (3) ◽  
pp. 137-147 ◽  
Author(s):  
David J. Ensing ◽  
Chandra E. Moffat ◽  
Jason Pither

Ecological niche models (ENMs) have been proposed and applied as tools for predicting the extent of exotic species invasion risk and for identifying areas at risk of invasion. Despite the acknowledged concern of relying on occurrence records of variable and (or) unknown quality, the effect of taxonomically uncertain occurrence records on ENMs has not been investigated. We first present a schematic model describing how taxonomic uncertainty could yield varying predictions of invasion potential depending on the spatial characteristics of all versus “reliable” occurrence records. We then explore the issue in more detail by way of a case study on the morphologically and taxonomically difficult yellowdevil hawkweed (Pilosella glomerata (Froel.) Fr.), which is invasive in North America. We compared the climate niche properties and ENM predictions of invasion risk by P. glomerata in North America among models based on (i) all available occurrence records and (ii) records that are taxonomically “reliable”. “Total” records yielded niche properties that were significantly more heterogeneous than reliable records, and consequently, the potential invasion range of P. glomerata based on total records was predicted to be substantially larger. Our results provide rare empirical evidence that vetting occurrence records for taxonomic reliability is of critical importance for niche modeling.


Nematology ◽  
2017 ◽  
Vol 19 (10) ◽  
pp. 1179-1199 ◽  
Author(s):  
Toon Janssen ◽  
Gerrit Karssen ◽  
Marjolein Couvreur ◽  
Lieven Waeyenberge ◽  
Wim Bert

Comprehensive morphological and molecular analyses revealed that published ITS sequences of the economically important plant-parasitic nematodePratylenchus goodeyiare actually sequences from distantly free-living bacterivorous ‘cephalobids’. We demonstrated that this incorrect labelling resulted in a cascade of erroneous interpretations, as shown by the reports of ‘P. goodeyi’ on banana in China and on cotton in India. This clearly illustrates the risk of mislabelled sequences in public databases. Other mislabelledPratylenchuscases are discussed to illustrate that this is not an isolated case. Herein,P. lentisn. syn. is considered a junior synonym ofP. pratensiswhileP. flakkensiswas for the first time linked to DNA sequences using topotype material. As taxonomic expertise is decreasing and sequence-based identification is growing rapidly, the highlighted problem may yet increase and a strong link between morphology and DNA sequences will be of crucial importance in order to prevent, or at least minimise, sequence-based misidentifications.


2015 ◽  
Vol 51 (5) ◽  
pp. 460-469 ◽  
Author(s):  
R. Timothy Patterson ◽  
Gail Huckerby ◽  
Thomas J. Kelly ◽  
Graeme T. Swindles ◽  
Nawaf A. Nasser
Keyword(s):  

The Holocene ◽  
1998 ◽  
Vol 8 (2) ◽  
pp. 209-218 ◽  
Author(s):  
Dan J. Charman ◽  
Helen M. Roe ◽  
W. Roland Gehrels

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