Morphological characterization of anterior axial bifurcation in <i>Holothuria</i> (<i>Halodeima</i>) <i>grisea</i> and other puzzling occurrences in Holothuroidea
Bibliographic record
Abstract
Abstract The present study explores rare but taxonomically and geographically widespread cases of anterior body axial bifurcation in adult sea cucumbers (Echinodermata: Holothuroidea). One individual of Holothuria ( Halodeima ) grisea , a common intertidal species along the Atlantic coast of Brazil, was studied externally and internally. Individuals of Apostichopus californicus from the northeastern Pacific coast of Washington (USA), H . ( Mertensiothuria ) leucospilota in the Indian Ocean off La Réunion, H . ( Panningothuria ) forskali from the Atlantic coast of Spain, and Parastichopus tremulus from the northeastern Atlantic off Norway were also reported to display similar anterior body axial bifurcation. In each of these species, the anterior body presented two mouths with their respective crown of tentacles. In vivo observations of H . ( Halodeima ) grisea showed that the two tentacle crowns and mouths were independently functional. Micro‐computed tomography (μCT) revealed that the anterior region of the body (up to the pharynx) was duplicated. Internally, two aquapharyngeal bulbs were found, each with their own calcareous ring (one with two plates missing), madreporite, and Polian vesicles. The body presented a normal set of five longitudinal muscle bands, some of which bifurcated orally to support more than one calcareous ring plate. This is the first report of such abnormalities in Holothuroidea and hypotheses that may explain such phenomenon are discussed.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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) | 0.000 | 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 teacher head, 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".