The gill slits and pre-oral ciliary organ of Protoglossus (Hemichordata: Enteropneusta) are filter-feeding structures
Bibliographic record
Abstract
898..907 Observations on the hemichordate worm Protoglossus graveolens demonstrate that the gill slits, pre-oral ciliary organ (POCO), and the lining of the cylindrical pharynx are used in filter feeding. Pumping of water is generated by cilia that line the lateral gill bars and the POCO directs water from the dorsal surface of the proboscis to the mouth. Particles are trapped and concentrated on the primary and secondary gill bars and transported ventrally and posteriorly by cilia that line the pharynx. The oesophageal organ functions as a barrier to water flow and to squeeze excess water from the mucus-food cord. Particles that passed freely through the gill pores were a maximum of 1.28 mm in size. Diluted milk entered the mouth and was pumped through the pharynx at a rate up to 4.05 mm s -1 . The Reynolds number and propulsive efficiency of the filter-feeding structures are estimated using algebraic models. Protoglossus elegantly orchestrates the movements of food particles captured by simultaneous filter feeding and deposit feeding or may, from one moment to the next, switch back and forth between deposit and filter feeding. Structural and functional similarities with the cephalochordate pharynx suggest that a wheel organ/ POCO and a filter-feeding pharynx may have been present in the common ancestor to the deuterostomes. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 898‐906. ADDITIONAL KEYWORDS: chordate origins ‐ deuterostome evolution ‐ Enteropneusta ‐ pharynx.
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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) | 0.002 | 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".