Molecular phylogenetic position of a rare and enigmatic meiofaunal flatworm from the Pacific Ocean: <i>Retronectes hyacinthe</i> sp. nov. (Platyhelminthes: Catenulida)
Bibliographic record
Abstract
Catenulids comprise the earliest diverging major lineage of flatworms. Although the majority of catenulid species live in fresh water, a small number of taxa have been documented from marine interstitial environments and most of these belong to the genera Retronectes and Paracatenula within the family Retronectidae. Representatives of Retronectes are extremely uncommon and almost only found in detritus-rich sand, with the last formal description of a species of Retronectes dating back to 1977. Little is known about the biology of the seven known species in this genus despite the fact that a unique combination of characters makes them relatively straightforward to recognize. Moreover, previous molecular phylogenetic analyses have so far been unable to include any representatives of Retronectes, so the phylogenetic position of these rarely encountered marine catenulids remains unclear. Here we describe a new species of Retronectes, namely R. hyacinthe sp. nov., from subtidal seagrass meadows in British Columbia (Canada) and present an updated phylogeny inferred from 18S and 28S rDNA sequences, including data from the new species of Retronectes and a selection of other catenulids. Our molecular phylogenetic trees suggest that Retronectidae sensu Sterrer & Rieger, 1974 Sterrer, W., & Rieger, R. (1974). Retronectidae—a new cosmopolitan marine family of Catenulida (Turbellaria). In N. W. Riser & M. P. Morse (Eds.), Biology of the Turbellaria (pp. 63–92). McGraw-Hill. [Google Scholar] is not monophyletic, implying that the current taxonomic classification of the Catenulida and the importance of certain morphological characters on which this classification is based are in need of revision.http://zoobank.org/urn:lsid:zoobank.org:pub:A38635FB-7A8A-4C11-B513-BDBF9EA780CB
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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".