Molecular phylogeny, taxonomic relationships and North American distribution of <i>Conchophthirus</i> (Conchophthiridae, Scuticociliatia)
Bibliographic record
Abstract
Conchophthirus curtus is a scuticociliate found in the mantle cavity of unionid bivalve mussels; it is considered by most to be an endocommensal. It was previously redescribed and its morphogenesis has been carefully defined and evaluated. Conchophthirus stomatogenesis along with its enigmatic deep kinetosomal unit as compared with other scuticociliates, peniculines, and peritrichs suggested possible homologies and affinities. Thus, a comparison of Conchophthirus with common molecular markers to all other ciliates was a goal of this study. We collected Conchophthirus spp. in California from two unionid bivalve hosts: Anodonta californiensis in the Pit River and Lake Merced, and Margaritifera falcata from the Trinity River. The ciliates analyzed were predominantly C. curtus although other conchophthirids were present. The small subunit rRNA and the cytochrome c oxidase subunit 1 genes were sequenced. Phylogenetic analyses of these data were analyzed and maximum likelihood for the small submit rRNA dataset and neighbor-joining for the cytochrome c oxidase subunit 1 dataset. The cytochrome c oxidase subunit 1 sequences obtained from M. falcata populations were virtually identical. The analysis placed these sequences with 96% bootstrap support as sister to Dexiotricha sp. The small submit rRNA sequences obtained from populations from both hosts were almost identical, and they showed them to be sister, with 99% support to two unpublished sequences from Chinese populations of Conchophthirus cucumis and C. lamellidens, and sister to a Dexiotricha sp. These data and their analyses confirm Conchophthirus to be a scuticociliate, but not closely related to either philasterine or pleuronematine scuticociliates nor the peniculines or peritrichs. Further analysis awaits additional data. The North American distribution of Conchophthirus, niche analyses, and potential homologous structures are discussed as well as the use of these endocommensals as indicators of water quality and pollution.
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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 | 0.000 | 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".