Morphological, biological, and molecular characteristics of the diatom<i>Pseudo-nitzschia delicatissima</i>from the Canadian MaritimesThis paper is one of a selection of papers published in the Special Issue on Systematics Research.
Bibliographic record
Abstract
Forty-six monoclonal cultures of the diatom Pseudo-nitzschia delicatissima (Cleve) Heiden were isolated from coastal waters of Eastern Canada. Of these, 12 clones were successfully sexualized. The range of their morphological and genetic divergence was used as a reference for clones whose sexual identity remains unknown. All characters that were examined, including valve morphology, the nuclear internal transcribed spacer (ITS) region, and mitochondrial cytochrome c oxidase (cox1) sequences, showed a high degree of similarity within and between mating and nonsexualized clones. Within the 638 bp long aligned fragment in the ITS region, only five variable sites were found and just two were found within the 576 bp fragment of cox1 near the 5′ terminus of the gene. Our own data and those retrieved from GenBank suggest that the northern North Atlantic is populated by a single metapopulation of genetically very similar P. delicatissima, as determined using the ITS sequence of the epitype of the species. The ITS region of our clones was distinct from ITS-types present in isolates that we will refer to as P. delicatissima-like diatoms from the Mediterranean Sea and other low latitude Atlantic sites, thereby providing a means to discriminate between otherwise morphologically indistinguishable (cryptic) species. Such a distribution pattern suggests different physiological and environmental requirements for mating optima. This work furthers our understanding of the relationship between biological, molecular, and morphological species boundaries in diatoms and their ecology, and contributes to evaluation of the utility of ITS and cox1 sequences in DNA barcoding of diatoms.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".