The first direct measurements of ventilatory flow and oxygen utilization after exhaustive exercise and natural feeding in a teleost fish, Oncorhynchus mykiss
Bibliographic record
Abstract
Abstract A new “less invasive” device incorporating an ultrasonic flow probe and a divided chamber, but no stitching of membranes to the fish, was employed to make the first direct measurements of ventilatory flow rate (V̇w) and % O2 utilization (%U) in juvenile rainbow trout (37 g, 8ºC) after exhaustive exercise (10-min chasing) and natural voluntary feeding (2.72% body mass ration). Under resting conditions, the allometrically scaled V̇w (300 ml kg−1 min−1 for a 37-g trout = 147 ml kg−1 min−1 for a 236-g trout exhibiting the same mass-specific O2 consumption rate, ṀO2) and the convection requirement for O2 (CR = 4.13 L mmol−1) were considerably lower, and the %U (67%) was considerably higher than in previous studies using surgically attached masks or the Fick principle. After exhaustive exercise, V̇w and ṀO2 approximately doubled whereas frequency (fr) and %U barely changed, so increased ventilatory stroke volume (Vsv) was the most important contributor to increased ṀO2. CR declined slightly. Values gradually returned to control conditions after 2–3 h. After voluntary feeding, short-term increases in V̇w, Vsv and ṀO2 were comparable to those after exercise, and fr again did not change. However, %U increased so CR declined even more. The initial peaks in V̇w, Vsv and ṀO2, similar to those after exercise, were likely influenced by the excitement and exercise component of natural feeding. However, in contrast to post-exercise fish, post-prandial fish exhibited second peaks in these same parameters at 1–3 h after feeding, and %U increased further, surpassing 85%, reflecting the true “specific dynamic action” response. We conclude that respiration in trout is much more efficient than previously believed.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| 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".