Morphology and molecular studies on large Neidium species (Bacillariophyta) of North America, including an examination of Ehrenberg’s types
Bibliographic record
Abstract
The genus Neidium contains a large array of diatoms with a wide range in structural and morphological forms. Many of the larger species in this genus are old taxa dating back to the 1800s. However, there continues to be confusion over these large species including N. iridis, N. dilatatum, N. firma, and N. amphigomphus. In this study, selected Neidium taxa from North America were examined using LM and SEM images from both Ehrenberg’s original samples and present day samples from Ontario (Canada) and New York State (USA). As well, Neidium individuals were isolated from Adriondack Park, NY (USA) and Ontario (Canada), amplified using a nested PCR protocol and sequenced for rbcL and 18S barcoding genes. The sequence data was concatenated to construct phylogenetic trees using Maximum Likelihood and Bayesian Analysis techniques. Here we present emended species descriptions and sequence data of four previously named Neidium taxa: N. tumescens, N. hitchcockii, N. dilatatum and N. amphigomphus. In addition, we designate isolectotypes for N. hitchcockii, N. dilatatum and N. amphigomphus. A new species is also formally described—N. fossum, sp. nov.—with a designated holotype and sequence data. Neidium fossum is distinguished by its size, longitudinal canal structure, central area and proximal raphe ends. Future work combining traditional morphological methods and phylogenetic methods will allow for further delineation of Neidium species and other diatom taxa.
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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 | 0.000 | 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".