Otolith and muscle stable isotope analyses to assess food-web interactions between threatened bigmouth buffalo (<i>Ictiobus cyprinellus</i>) and invasive common carp (<i>Cyprinus carpio</i>)
Bibliographic record
Abstract
Long-lived bigmouth buffalo ( Ictiobus cyprinellus) are declining and a species of special concern in central Canada whose densities may be impacted by invasive common carp ( Cyprinus carpio). In addition, the bigmouth buffalo is a culturally important species for the File Hills Qu'Appelle Tribal Council Member First Nations, who have harvested them since time immemorial. Here we analyzed δ13C and δ15 N in bigmouth buffalo and common carp muscle tissue, along with bulk and compound-specific amino-acid δ15 N of otoliths, to examine the food-web interactions of species over the past 100 years. Stable isotope ratios of muscle tissue inferred that the fishes generally occupied different isotopic niches, with bigmouth buffalo exhibiting greater evidence of pelagic feeding (mean ± SD; 88 ± 22% and 42 ± 13% in two lakes), and higher trophic position (3.6 ± 0.3 and 3.8 ± 0.3) than common carp (74 ± 11% and 33 ± 13%; 3.2 ± 0.4 and 3.4 ± 0.3, respectively). Overall, modern otolith isotope values agreed with paired muscle isotope values, while bulk otolith material exhibited increased δ15 N over a century. Apparent isotopic niche differentiation between the species may have arisen from ongoing niche displacement by common carp following watershed invasion ca. 1955. This competition may be more intense for larger bigmouth buffalo.
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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 | 0.001 |
| 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) | 0.001 | 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".