Supplementary material from "Do air-breathing fish suffer branchial oxygen loss in hypoxic water?"
Bibliographic record
Abstract
In hypoxia, air-breathing fish obtain O<sub>2</sub> from the air but continue to excrete CO<sub>2</sub> into the water. Consequently, it is believed that some O<sub>2</sub> obtained by air-breathing is lost at the gills in hypoxic water. <i>Pangasionodon hypophthalmus</i> is an air-breathing catfish with very large gills from the Mekong River basin where it is cultured in hypoxic ponds. To understand how <i>P. hypophthalmus</i> can maintain high growth in hypoxia with the presumed O<sub>2</sub> loss, we quantified respiratory gas exchange in air and water. In severe hypoxia (PO<sub>2</sub>: ≈ 1.5 mmHg), it lost a mere 4.9% of its aerial O<sub>2</sub> uptake, while maintaining aquatic CO<sub>2</sub> excretion at 91% of the total. Further, even small elevations in water PO<sub>2</sub> rapidly reduced this minor loss. Charting the cardiovascular bauplan across the branchial basket showed four ventral aortas leaving the bulbus arteriosus, with the first and second gill arches draining into the dorsal aorta while the third and fourth gill arches drain into the coeliacomesenteric artery supplying the gut and the highly trabeculated respiratory swim-bladder. Substantial flow changes across these two arterial systems from normoxic to hypoxic water were not found. We conclude that the proposed branchial oxygen loss in air-breathing fish is likely only a minor inefficiency.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 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) | 0.977 | 0.012 |
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; both teacher heads agree on what is shown here.
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".