Description and molecular phylogeny of Tethya leysae sp. nov. (Porifera, Demospongiae, Hadromerida) from the Canadian Northeast Pacific with remarks on the use of microtomography in sponge taxonomy
Bibliographic record
Abstract
The sponge Tethya leysae sp. nov. (Porifera, Demospongiae, Hadromerida, Tethyidae) is a new species from the Canadian Northeast Pacific. Its type locality is the infralittoral around Ohiat Islet, Barkely Sound, Vancouver Island in Canada. Tethya leysae sp. nov. is a medium-sized spherical sponge with a verrucose surface, orange-yellow to light red alive and white with a greyish core in ethanol. The highly variable oxyspherasters (25-115 µm in size, R/C 0.34-0.69) are densely scattered almost throughout the entire cortex. The micrasters comprise acanthoxyspherasters, acanthostrongylasters, acanthotylasters and small oxyspherasters, which are present at low densities throughout the sponge and form a dense layer associated with the exopinacoderm. The megascleres and the auxiliary megascleres comprise oxeas and strongyloxeas. The new species is clearly distinguishable from the closely related T. californiana by the absence of spherules among the micrasters, the lack of an alveolar cortex and the extremely high density of megasters in the cortex. In addition, the R/C values of the megasters differ between the two species and the oxyspherasters of T. leysae sp. nov. rarely display bent rays. The morphological differences between the species are confirmed by nucleotide and amino acid substitutions within the cytochrome oxidase subunit I (COI) mtDNA gene. Phylogenetic analyses group T. leysae sp. nov. with T. californiana, T. actinia and T. minuta, which together form a sister group to a MediterraneanNorth Atlantic species cluster. Morphological analyses of the skeleton included x-ray microtomography (µCT) and virtual 3D reconstruction, which was used for the first time in conjunction with the description of a new sponge species. Microtomography permitted the visualization and analysis of spicules within the skeletal context or isolated in silico. The method represents a valuable extension to the sponge taxonomist’s toolbox since it allows morphometric measurements in 3D. µCT will thus supplement classical morphological methods such as light and scanning electron microscopy.
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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 | 0.003 | 0.004 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".