Recognition of <i>Rubrointrusa membranacea</i> gen. et comb. nov., <i>Rhodonematella subimmersa</i> gen. et comb. nov. (with a reinterpretation of the life history) and the Meiodiscaceae fam. nov. within the Palmariales (Rhodophyta)
Bibliographic record
Abstract
Clayden S.L. and Saunders G.W. 2010. Recognition of Rubrointrusa membranacea gen. et comb. nov., Rhodonematella subimmersa gen. et comb. nov. (with a reinterpretation of the life history) and the Meiodiscaceae fam. nov. within the Palmariales (Rhodophyta). Phycologia 49: 283–300. DOI: 10.2216/09-43.1Two members currently classified in the florideophyte Colaconematales, Colaconema membranaceum and C. subimmersum, display life history and morphological/anatomical characteristics suggestive of some Palmariales, prompting the current investigation. We observed a direct life history by regenerative tetrasporangia for C. membranaceum as previously reported and provide the first evidence of sexual reproduction in C. subimmersum from the Pacific northeast, corroborating reports from Japan. However, the life history pattern in C. subimmersum is reinterpreted as intermediate between that typical of the Palmariaceae and Rhodophysemataceae. We addressed the phylogenetic affinities of these two species by sequencing large-subunit ribosomal DNA and the ‘DNA barcode’ (5′ region of the cytochrome oxidase subunit I gene), which was also used to assess species diversity. In phylogenetic analyses both C. membranaceum and C. subimmersum were unequivocally supported as members of the Palmariales. Colaconema membranaceum displayed a weak affinity for species of Meiodiscus but is distinct in its endozoic basal system, and we propose Rubrointrusa gen. nov., typified by Rubrointrusa membranacea (Magnus) comb. nov. Colaconema subimmersum, consistently grouped with species of Rhodophysema but is divergent from these species in habit, life history, and molecular signature, so that we propose a new monotypic genus Rhodonematella, typified by Rhodonematella subimmersa (Setchell & N.L. Gardner) comb. nov. Rhodonematella, is provisionally placed in the Rhodophysemataceae. We concomitantly examined the phylogenetic affinities of Halosacciocolax kjellmanii and Meiodiscus spp., both tentatively included in the Rhodophysemataceae. Halosacciocolax kjellmanii is retained in the Rhodophysemataceae and transferred to Rhodophysema, Rhodophysema kjellmanii (S. Lund) comb. nov., based on our molecular results and new anatomical observations. Conversely, Meiodiscus species resolved independently of other palmarialean families, and we propose the Meiodiscaceae fam. nov. to accommodate them, as well as Rubrointrusa. Meiodiscus concrescens is restricted to populations from the northeast Pacific; whereas, so-called Atlantic M. concrescens is conspecific with M. spetsbergensis.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.003 |
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".