SCUTICOCILIATE ENDOSYMBIONTS OF ECHINOIDS (PHYLUM ECHINODERMATA): PHYLOGENETIC RELATIONSHIPS AMONG SPECIES IN THE GENERA ENTODISCUS, PLAGIOPYLIELLA, THYROPHYLAX, AND ENTORHIPIDIUM (PHYLUM CILIOPHORA)
Bibliographic record
Abstract
Morphological research on over 50 species of ciliates recorded as endosymbionts of echinoids suggests that invasion of the echinoid microhabitat occurred on at least 4 occasions. Gene sequence data confirm the phylogenetic distinctness of spirotrichean, armophorean, plagiopylean, and oligohymenophorean endosymbionts. It is also likely that oligohymenophoreans have repeatedly invaded the gut habitat. To test this hypothesis, we sequenced small subunit rRNA (SSrRNA) genes of 6 species representing the larger scuticociliate species found in the intestine of Strongylocentrotus pallidus from the northeast Pacific Ocean: Entodiscus borealis (Entodiscidae); Plagiopyliella pacifica and Thyrophylax vorax (Thyrophylacidae); and Entorhipidium pilatum, Entorhipidium tenue, and Entorhipidium sp. (Entorhipidiidae). SsrRNA genes were amplified by PCR, and sequences obtained in both directions. In all phylogenetic analyses, the scuticociliates are well supported as a clade. Entodiscus is distinct from these other echinoid taxa and is the sister taxon to the facultatively parasitic Uronema marinum. The other 5 echinoid species always form a clade whose basal species is the free-living Parauronema longum. The greatest genetic distance among these latter 5 species is less than 1.5%. This probably explains why the Thyrophylacidae and Entorhipidiidae are paraphyletic based on the SSrRNA gene sequences.
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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 | 0.000 |
| 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) | 0.001 | 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".