Rediscovery of Nebela ansata (Amoebozoa: Arcellinida) in eastern North America: biogeographical implications
Bibliographic record
Abstract
<i>Aim:</i> The question whether free-living protists are generally cosmopolitan is currently a matter of debate. In this study we investigate the geographical distribution of a distinctive testate amoeba species, <i>Nebela ansata</i>, and use our data to assess the potential for highly restricted distribution patterns in some protist species.\n<br/>\n<i>Location:</i> Global.\n<br/>\n<i>Methods:</i> We analysed (1) 3400 testate amoeba publications from North America and other continents, (2) unpublished slides of the Penard Collection of the Natural History Museum, London, UK, and (3) 104 <i>Sphagnum</i> samples from eastern North America. Non-metric multidimensional scaling (NMDS) was used to visualize the similarities in testate amoeba community composition among 1012 North American samples, including two communities that contained <i>N. ansata</i>.\n<br/>\n<i>Results:</i> We rediscovered <i>N. ansata</i> at a site in New Jersey located close to its type locality, and in Nova Scotia. We also report the existence of an apparently unpublished museum specimen originally collected from New Jersey. Our extensive literature survey confirmed the presence of this species only in the temperate part of eastern North America. The NMDS revealed that communities with <i>N. ansata</i> were less similar to each other than to communities from other parts of North America, suggesting that favourable habitats for <i>N. ansata</i> occur in other <i>Sphagnum</i>-dominated peatlands, a habitat type that has been extensively sampled in North America and elsewhere. \n<br/>\n<i>Main conclusions:</i> These data provide an unusually convincing case of a free-living microorganism with a very limited distribution range in the temperate part of eastern North America. The remarkably restricted distribution of <i>N. ansata</i> highlights the extent of our ignorance about the natural history of free-living microorganisms, and raises questions about the lack of attention to microbial diversity in conservation biology.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".